SECOND DRAFT Contents Preamble Chapter 1 Introduction Rationale Curriculum Aims Chapter 2 Chapter 3 1 2 Curriculum Framework Curriculum Structure Learning Targets Compulsory Part Elective Part 3 6 8 43 Investigative Study 79 Curriculum Planning Interfacing Junior Secondary Science Curriculum Progression of Studies Suggested Learning and Teaching Sequences Chapter 4 Learning and Teaching Designing Learning Activities Teaching with a Contextual Approach Using Information Technology (IT) for Interactive Learning Providing Life-wide Learning Opportunities Chapter 5 83 85 88 92 95 95 95 Assessment Aims of Assessment Internal Assessment Public Assessment 96 96 96 Chapter 6 Effective Use of Learning and Teaching Resources 100 Chapter 7 Supporting Measures 101 References 102 i SECOND DRAFT ii SECOND DRAFT Preamble The Curriculum Development Council (CDC)-Hong Kong Examinations and Assessment Authority (HKEAA) Committees (Senior Secondary) of various subjects have been set up jointly by the CDC and the HKEAA Council to develop the Curriculum and Assessment Guides (C&A Guides) for the new 3-year senior secondary academic structure in Hong Kong. During the first stage of consultation on the new academic structure between October 2004 and January 2005, the document Reforming the Academic Structure for Senior Secondary Education and Higher Education - Actions for Investing in the Future (Education and Manpower Bureau, 2004) was published to seek stakeholders’ views on the design blueprint of the structure, the timetable for implementation and financial arrangements. An accompanying document, Proposed Core and Elective Subject Frameworks for the New Senior Secondary Curriculum, was also produced to solicit views and feedback from schools on the initial curriculum and assessment design of individual subjects to inform the development of the C&A Guides. The report New Academic Structure for Senior Secondary Education and Higher Education – Action Plan for Investing in the Future of Hong Kong (Education and Manpower Bureau, 2005), an outcome of the first stage of consultation, has just been published to chart the way forward for implementing the new academic structure and to set further directions for the second stage of consultation on curriculum and assessment as part of the interactive and multiple-stage process of developing the C&A Guides. In addition, taking into consideration the feedback collected through various means including the returned questionnaires from key learning area coordinators/panel heads during the first stage of consultation, the curriculum and assessment frameworks of subjects have been revised and elaborated. We would like to solicit further views on the frameworks from stakeholders, in particular the school sector. To understand the position of each subject in the new academic structure, readers are encouraged to refer to the report. Comments and suggestions on the Proposed New Senior Secondary Physics Curriculum and Assessment Framework are welcome and could be sent to: Chief Curriculum Development Officer (Science Education) 401, 4/F., Tin Kwong Road, Kowloon Fax: 2194 0670 E-mail: science@emb.gov.hk iii SECOND DRAFT iv SECOND DRAFT Chapter 1 Introduction 1.1 Physics is one of the elective subjects in the Key Learning Area (KLA) of Science Education 1 . The Physics Curriculum serves as a continuation of the Science (S1-3) Curriculum and builds on the strength of the current Physics Curricula. It will provide a range of balanced learning experiences through which students can develop the necessary scientific knowledge and understanding, skills and processes, and values and attitudes embedded in the strand “Energy and Change” of science education and in other related strands for personal development, and for contributing towards a scientific and technological world. The curriculum will prepare students for entering tertiary courses, vocation-related courses or joining the workforce in various fields of physical science. Rationale 1.2 The emergence of a highly competitive and integrated economy, rapid scientific and technological innovations, and a growing knowledge base will continue to have a profound impact on our lives. In order to meet the challenges posed by these changes, Physics, like other science electives, will provide a platform for developing scientific literacy and for building up essential scientific knowledge and skills for life-long learning in science and technology. 1.3 Physics is one of the most fundamental natural sciences. It involves the study of universal laws, and the behaviours and relationships among a wide range of physical phenomena. Through the learning of physics, students will acquire conceptual and procedural knowledge relevant to their daily lives. In addition to the relevance and intrinsic beauty of physics, the study of physics also helps students to develop an understanding of the practical applications of physics to a wide variety of other fields. With a solid foundation in physics, students should be able to appreciate the intrinsic beauty and quantitative nature of physical phenomena, and the role of physics in many important developments in engineering, medicine, economics and other fields of science and technology. Furthermore, learning about the contribution, issues and problems related to innovations in physics will help 1 There will be four elective subjects offered in the Key Learning Area of Science Education, namely Biology, Chemistry, Physics and Science. The design of the subject Science will include two modes – integrated and combined. This curriculum will contribute towards the Physics part of the combined mode – Science (Biology, Physics) and Science (Physics, Chemistry). 1 SECOND DRAFT students to develop a holistic view of the relation of science, technology, society and the environment. 1.4 The curriculum attempts to make the study of physics exciting and relevant. It is suggested to introduce the learning of physics in real life contexts. The adoption of diverse learning contexts, learning and teaching strategies, and assessment practices is intended to appeal to students of all abilities and aspirations, and to stimulate interest and motivation for learning among them. Together with other learning experiences, students are expected to be able to apply the knowledge of physics they gain, to appreciate the relationship between physics and other disciplines, to be aware of the science-technology-society-environment (STSE) connections of contemporary issues, and to become responsible citizens. Curriculum Aims 1.5 The overarching aim of the Physics Curriculum is to provide physics-related learning experiences for students to develop scientific literacy, so that they can participate actively in our rapidly changing knowledge-based society, prepare for further studies or careers in fields related to physics, and become life-long learners in science and technology. The broad aims of the curriculum are to enable students to: develop interest and maintain a sense of wonder and curiosity about the physical world; construct and apply knowledge of physics, and appreciate the relationship between physical science and other disciplines; appreciate and understand the nature of science in physics-related contexts; develop skills for making scientific inquiries; develop the ability to think scientifically, critically and creatively, and to solve problems individually or collaboratively in physics-related contexts; understand the language of science and communicate ideas and views on physics-related issues; make informed decisions and judgments on physics-related issues; and be aware of the social, ethical, economic, environmental and technological implications of physics, and develop an attitude of responsible citizenship. 2 SECOND DRAFT Chapter 2 Curriculum Framework Curriculum Structure 2.1 The curriculum will consist of compulsory and elective parts. The compulsory part will cover a range of content that enables students to develop understanding of fundamental principles and concepts in physics, and the scientific process skills. It is suggested to include the following topics: “Heat Transfer and Gases”, “Force and Motion”, “Wave Motion”, “Electricity and Magnetism” and “Radioactivity and Nuclear Energy”. 2.2 To cater for the diverse interests, abilities and needs of students, an elective part will be included in the curriculum. The elective part aims to provide an in-depth treatment of some of the topics in the compulsory part, an extension of certain areas of study, or a synthesis of knowledge, understanding and skills in a particular context. Topics suggested in the elective part are: “Astronomy and Space Science”, “Atomic World”, “Energy and Use of Energy” and “Medical Physics”. 2.3 To facilitate the integration of knowledge and skills acquired, students are required to conduct an investigative study relevant to the curriculum. A proportion of lesson time will be allocated for this study. 2.4 The suggested content and time allocation for the compulsory and elective parts are listed in the following tables. Suggested lesson time (hrs) Compulsory part (Total 200 hours) * I. Heat Transfer and Gases II. Force and Motion a. b. c. d. a. b. c. d. e. f. Temperature, heat and internal energy* Transfer processes* Change of state* Gases Position and movement* Force and motion* Motion in two dimensions* Work, energy and power* Momentum* Gravitation 25 55 Parts of these topics are proposed to be included in the physics part of Science (Biology, Physics) and that of Science (Chemistry, Physics) respectively. 3 SECOND DRAFT Compulsory part (Total 200 hours) III. Wave Motion IV. Electricity and Magnetism V. Radioactivity and Nuclear Energy a. b. c. a. b. c. a. b. c. Suggested lesson time (hrs) Nature and properties of waves* Light* Sound* Electrostatics* Circuits and domestic electricity* Electromagnetism* Radiation and radioactivity Atomic model Nuclear energy Subtotal: Astronomy and Space Science VII. Atomic World VIII. Energy and Use of Energy IX. Medical Physics Study in Physics * 200 The universe as seen in different scales Astronomy through history Newton’s law of gravitation Stars and the universe Rutherford’s atomic model Photoelectric effect Bohr’s atomic model of hydrogen Particles or waves Probing into nano scale Electricity at home Energy performance in building and transportation c. Renewable sources of energy 27 a. Making sense of the eye and the ear b. Sound and optical imaging c. Medical imaging 27 27 27 54 Suggested lesson time (hrs) Investigative Study (16 hours) Investigative 16 a. b. c. d. a. b. c. d. e. a. b. Subtotal: X. 56 Suggested lesson time (hrs) Elective part (Total 54 hours, any 2 out of 4) VI. 48 Students should conduct an investigation with a view to solving an authentic problem 16 Total lesson time: 270 Parts of these topics are proposed to be included in the physics part of Science (Biology, Physics) and that of Science (Chemistry, Physics) respectively. 4 SECOND DRAFT 2.5 The content of the curriculum is organised into 9 topics and an investigative study. However, the concepts and principles of physics are inter-related, which cannot be confined by any artificial boundaries of topics. The order of presentation of the topics in this chapter should not be regarded as the recommended teaching sequence. Teachers should adopt sequences that best suit their chosen teaching approaches as well as the benefit of students’ learning. For instance, some parts of a certain topic may be covered in advance if they fit in naturally with a chosen context. 2.6 There are five major parts in each of the following nine topics: Overview, Learning Outcomes, Suggested Learning and Teaching Activities, Values and Attitudes, and Science, Technology, Society and Environment (STSE) connections. Overview – outlines the main theme of the topic. The major concepts and important physics principles to be acquired will be highlighted. The foci of each topic will be briefly described. The interconnections between subtopics will also be outlined. Learning Outcomes – lists out the learning outcomes acquired by students in the knowledge content domain of the curriculum. It provides a broad framework upon which learning and teaching activities can be developed. Suggested Learning and Teaching Activities – gives suggestions to some of the different skills that are expected to be acquired in the topic. Some important processes associated with the topic are also briefly described. Since most of the generic skills can be acquired through any of the topics, there is no attempt to give directive recommendation on the activities that should be performed. Students need to acquire a much broader variety of skills than what are mentioned in the topics. Teachers should exercise their professional judgement to arrange practical and learning activities to develop the skills of students as listed in the Skills and Process of the Curriculum Framework. It should be done through appropriate integrations with the knowledge content, taking into consideration of students’ abilities and interests as well as school contexts. Values and Attitudes – suggests some desirable values and attitudes related to the study in the topic. Students are expected to develop such intrinsically worthwhile values and positive attitudes in the course of study in physics. Through discussions and debates, for example, students are encouraged to form their value judgement and develop good habits for the benefit of themselves and the society. 5 SECOND DRAFT STSE connections – suggests some issue-based learning activities or contexts related to the topic. Students should be encouraged to develop an appreciation and apprehension of issues which reflect the interconnections of science, technology, society and the environment. Through discussion, debate, information search and project work, students can develop their skills of communication, information handling, critical thinking and making informed judgement. Teachers are free to select other current, relevant topics and issues of high profile in the public agenda as themes of meaningful learning activities. Learning Targets 2.7 The learning targets of this curriculum are categorised into three domains: knowledge and understanding, skills and processes, and values and attitudes. Through the learning embodied in the Physics Curriculum, students will reach the relevant learning targets in various physics-related contexts. Knowledge and Understanding Students are expected to: understand phenomena, facts and patterns, principles, concepts, laws, theories and models in physics; learn vocabulary, terminology and conventions in physics; acquire knowledge of techniques and skills specific to the study of physics; group and organise knowledge and understanding in physics, and apply them to familiar and unfamiliar situations; and develop an understanding of technological applications of physics and of their social implications. Skills and Processes Students are expected to: develop scientific thinking and problem-solving skills; develop an analytical mind to critically evaluate physics-related issues; communicate scientific ideas and values in meaningful and creative ways with appropriate use of diagrams, symbols, formulae, equations and conventions, as 6 SECOND DRAFT well as verbal means; acquire practical skills such as how to manipulate apparatus and equipment, carry out given procedures, analyse and present data, draw conclusions and evaluate experimental procedures; make careful observations, ask relevant questions, identify problems and formulate hypotheses for investigation; plan and conduct scientific investigations individually or collaboratively with appropriate instruments and methods, collect quantitative and qualitative data with accuracy, analyse and present data, draw conclusions, and evaluate evidence and procedures; and develop study skills to improve the effectiveness and efficiency of learning; and develop abilities and habits that are essential to life-long learning. Values and Attitudes Students are expected to: develop positive values and attitudes such as curiosity, honesty, respect for evidence, perseverance and tolerance of uncertainty through the study of physics; develop a habit of self-reflection and the ability to think critically; be willing to communicate and comment on issues related to physics, and demonstrate open-mindedness towards the views of others; be aware of the importance of safety for themselves and others, and be committed to safe practices in their daily life; appreciate the achievements made in physics and recognise their limitations; be aware of the social, economic, environmental and technological implications of achievements in physics; and recognise the importance of life-long learning in our rapidly changing knowledge-based society. 7 SECOND DRAFT Compulsory Part (200 hours) Topic I Heat Transfer and Gases (25 hours) Overview This topic examines the concept of thermal energy and transfer processes which are crucial for the maintenance and quality of our lives. Particular attention is placed on the distinction and relationship among temperature, internal energy and energy transfer. Students are also encouraged to adopt microscopic interpretations of various important concepts on the topic of thermal physics. Calculations involving specific heat capacity will serve to complement the theoretical aspects of heat and energy transfer. The practical importance of the high specific heat capacity of water can be illustrated with examples close to the experiences of students. A study of conduction, convection and radiation provides a basis for analysing the containment of internal energy and transfer of energy related to heat. The physics involving the change of states is examined and numerical problems involving the specific latent heat are used to consolidate the theoretical aspects of energy conversion. The ideal gas law relating the pressure, temperature and volume of an ideal gas was originally derived from the experimentally measured Charles' law and Boyle's law. Many common gases exhibit behaviour very close to that of an ideal gas at ambient temperature and pressure. The ideal gas law is a good approximation to study the properties of gases because it does not deviate much from the ways that real gases behave. The kinetic theory of gases is intended to correlate temperature to the kinetic energy of gas molecules and interpret pressure in terms of the motion of gas molecules. 8 SECOND DRAFT Learning Outcomes Students should learn: a. Students should be able to: Temperature, heat and internal energy temperature and thermometers realise temperature as the degree of hotness of an object interpret temperature as a quantity associated with the average kinetic energy due to the random motion of molecules in a system account for the use of temperature-dependent properties to measure temperature use degree Celsius as a unit of temperature reproduce fixed points on the Celsius scale b. heat and internal energy realise heat as the energy transferred resulting from the temperature difference between two objects realise internal energy as the energy stored in a system interpret internal energy as the sum of the kinetic energy of random motion and the potential energy of molecules in a system heat capacity and specific heat capacity define heat capacity and specific heat capacity apply formula Q = mc(T2-T1) to solve problems consider the practical importance of the high specific heat capacity of water Transfer processes conduction, convection and radiation classify means of energy transfer in terms of conduction, convection and radiation interpret energy transfer by conduction and convection in terms of molecular motion identify emission of infra-red radiation by hot objects determine factors affecting the emission and absorption of radiation 9 SECOND DRAFT Students should learn: c. Students should be able to: Change of state melting and freezing, boiling and condensing determine melting point and boiling point latent heat realise latent heat as the energy transferred during the change of state at constant temperature interpret latent heat in terms of the change of potential energy of the molecules during change of state define specific latent heat of fusion and specific latent heat of vaporization apply formula Q = ml to solve problems evaporation d. examine the occurrence of evaporation below boiling point account for the cooling effect of evaporation determine the factors affecting rate of evaporation interpret evaporation in terms of molecular motion Gases ideal gases define pressure p = F/A determine pressure-temperature and volume-temperature relationships of a gas determine absolute zero by the extrapolation of p-T or V-T relationship verify Boyle’s law by an experimental investigation combine the three relationships of a gas to obtain the general gas law pV = nRT 10 SECOND DRAFT Students should learn: kinetic theory of gases Students should be able to: define an ideal gas state the assumptions for the kinetic model of gases derive pV = Nmc 2 / 3 interpret keaverage temperature 3RT = 2N A for an ideal gas using Suggested Learning and Teaching Activities Students should develop experimental skills in measuring temperature, volume, pressure and energy. The precautions essential for accurate measurements in heat experiments should be understood in terms of the concepts learnt in this topic. Students should also be encouraged to suggest their own methods for improving the accuracy of these experiments, and arrangement for performing these investigations should be made if they are feasible. In some of the experiments, a prior knowledge of electrical energy may be required to facilitate a solid understanding of the energy transfer processes involved. There is much emphasis in the importance of graphical representations of physical phenomena in this topic. Students should learn how to plot graphs with suitable choices of scales, display experimental results graphically and interpret, analyse and draw conclusions from graphical information. In particular, they should learn to extrapolate the trends of the graphs to determine the absolute zero of the temperature. Students should be able to plan and interpret information from different types of data sources. Most experiments and investigations will produce a set of results which may readily be compared with those data in textbooks and handbooks. The possible learning contexts that students may experience are suggested below for reference: Studying the random motion of molecules inside a smoke cell using microscope and video camera Performing an experiment to show how to measure temperature using a device with temperature-dependent property 11 SECOND DRAFT Calibrating a thermometer Reproducing fixed points on the Celsius scale Performing experiments to determine specific heat capacity and latent heat Measuring the specific latent heat of fusion of water (e.g. using a domestic electric boiler, heating an ice-water mixture in a composite container, or using ice calorimeter) Performing experiments to study the cooling curve of a substance and determine its melting point Performing experiments to study the relationship among volume, pressure and temperature of a gas Determining factors affecting the rate of evaporation Asking students to feel their sensation of coldness by touching few substances in the kitchen and clarifying some misconceptions that may arise from their daily experiences Fostering students’ knowledge of conduction, convection, radiation, greenhouse effect and heat capacity by designing and constructing a solar cooker Challenging students’ preconceived ideas on heat transfer by posing appropriate competitions (e.g. attaining a temperature closest to 4oC by mixing soft drink with ice) Facilitating students to use dimension analysis to check results of mathematical solutions Investigating properties of a gas using simulations or modelling Reading articles on heat stroke and discussing heat stroke precautions and care Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the proper use of heat-related domestic appliances as it helps to reduce the cost of electricity and contributes to the worthwhile cause of saving energy to be aware of the large amount of energy associated with heat transfer and to develop good habits in using air-conditioning in summer and heating in winter to develop an interest in using alternative environmental friendly energy resources such as solar and geothermal energy to be aware of the importance of home safety in relation to the use of radiation heater and to be committed to safe practices in their daily life 12 SECOND DRAFT STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the importance of greenhouses in agriculture and the environmental issues of ‘Greenhouse Effect’ debates on the gradual rise in global temperature due to human activities, the associated potential global hazards due to the melting of the polar ice caps and the effects on the world’s agricultural production projects, such as the ‘Design of Solar Cooker’, can be used to develop the investigation skills as well as to foster the concept of using alternative environmental friendly energy resources 13 SECOND DRAFT Topic II Force and Motion (55 hours) Overview Motion is common to our daily experiences. It is an important feature in physics to describe how objects move and investigate why objects move in the way they do. In this topic, the fundamentals of mechanics in kinematics and dynamics are introduced, and the foundation for describing motion with physics terminology is laid. Various types of graphical representations of motion are studied. Students learn how to analyse different forms of motion and solve simple problems relating to uniformly accelerated motion. They also learn about motion in one or two dimensions and rules governing the motion of objects on Earth. The concept of inertia and its relation to Newton’s First Law of motion are covered. Simple addition and resolution of forces are used to illustrate the vector properties of forces. Free-body diagrams are used to work out the net force acting on a body. Newton’s Second Law of motion, which relates the acceleration of an object to the net force, is examined. The concepts of mass, weight and gravitational force are introduced. Newton’s Third Law of motion is related to the nature of forces. The study of motion is extended to 2 dimensions, including projectile motion and circular motion which lead to an investigation of gravitation. Work is a process of energy transfer. The concepts of mechanical work done and energy transfer are examined and used in the derivation of kinetic energy and gravitational potential energy. Conservation of energy in a closed system is a fundamental concept in physics. The treatment of energy conversion is used to illustrate the law of conservation of energy, and the concept of power is also introduced. Students learn how to compute quantities such as momentum and energy in examples involving collisions. The relationship among the change in momentum of a body, impact time and impact force is emphasized. Learning Outcomes Students should learn: a. Students should be able to: Position and movement position, distance and displacement describe the change of position of objects in terms of distance and displacement 14 SECOND DRAFT Students should learn: Students should be able to: present information graphically of displacement-time graphs for moving objects scalars and vectors distinguish between scalar and vector quantities use scalars and vectors in different contexts speed and velocity define average speed and average velocity distinguish between instantaneous and average speed/velocity describe motion of objects in terms of speed and velocity present information on velocity-time graphs for moving objects linear uniform motion interpret uniform motion of objects using algebraic and graphical methods use displacement-time and velocity-time graphs to determine the displacement and velocity of objects solve problems involving displacement, time and average velocity acceleration define acceleration as the rate of change of velocity use velocity-time graphs to determine the acceleration of objects in uniformly accelerated motion present information on acceleration-time graphs for moving objects equations of uniformly accelerated motion derive equations of uniformly accelerated motion v = u + at s = 12 (u + v)t s = ut + 12 at 2 v 2 = u 2 + 2as solve problems for objects in uniformly accelerated motion 15 SECOND DRAFT Students should learn: vertical motion under gravity b. Students should be able to: analyse and describe the motion of free-falling objects present graphically information of vertical motions under gravity solve problems for objects in vertical motion using the equations of uniformly accelerated motion describe the effects of air resistance on the motion of objects falling under gravity Force and motion Newton’s First Law of motion describe the meaning of inertia and mass realise Newton’s First Law of motion and apply it to explain situations in which objects are at rest or in uniform motion realise friction as a force opposing motion addition of forces find the vector sum of coplanar forces graphically and algebraically resolution of forces resolve a force graphically and algebraically into components along two mutually perpendicular directions Newton’s Second Law of motion realise the effect of a net force on the speed and/or direction of motion of an object understand Newton’s Second Law of motion and the formula F = ma use newton as a unit of force use free-body diagrams to show the forces acting on objects identify the net force in a system consisting of one or two objects solve problems involving rectilinear motion Newton’s Third Law of motion realise forces acting in pairs understand Newton’s Third Law of motion and apply it to 16 SECOND DRAFT Students should learn: Students should be able to: identify action and reaction pair of forces c. d. mass and weight distinguish between mass and weight realise the relationship between mass and weight moment of a force define moment of a force as the product of the force and its perpendicular distance from the pivot recognise the use of torques and couples state the conditions for equilibrium of forces acting on a point mass and a rigid body determine the centre of gravity experimentally Motion in two dimensions projectile motion describe the shape of the path taken by a projectile launched at an angle of projection realise the independence of vertical and horizontal motions resolve a projectile’s velocity into horizontal and vertical components solve problems involving projectile motion circular motion understand angular velocity and realise its relationship between it and linear velocity derive centripetal acceleration a = v2/r solve problems involving circular motion Work, energy and power mechanical work realise mechanical work done as a measure of energy transfer define mechanical work done W = Fs cosθ solve problems involving mechanical work 17 SECOND DRAFT Students should learn: Students should be able to: gravitational potential energy (P.E.) realise gravitational potential energy of an object due to its position under the action of gravity derive the formula EP = mgh solve problems involving gravitational potential energy kinetic energy (K.E.) realise kinetic energy of an object due to its motion derive the formula E K = ½ mv 2 solve problems involving kinetic energy e. law of conservation of energy in a closed system interpret the law of conservation of energy realise inter-conversion of P.E. and K.E. and take into account of the energy loss apply the law of conservation of energy to solve problems power define power in terms of the rate of energy transfer use watt as a unit of power W apply the formula P = to solve problems t Momentum linear momentum define momentum as a quantity of motion of an object change in momentum and net force realise the change in momentum resulted when a net force acts on an object for a period of time interpret force as the rate of change of momentum (Newton’s Second Law of motion) law of conservation of momentum interpret the law of conservation of momentum elastic and inelastic collisions distinguish between elastic and inelastic collisions apply the law of conservation of momentum to solve problems involving collisions in one dimension 18 SECOND DRAFT Students should learn: Students should be able to: describe energy changes in collisions f. Gravitation Gravitational force between masses state Newton’s law of universal gravitation Field strength g define gravitational field strength as force per unit mass derive g = G M / r 2 solve problems involving gravitation Suggested Learning and Teaching Activities Students should develop experimental skills in measuring time and in the recording of positions, velocities and accelerations of objects using various types of measuring instruments such as stop watches, data-logging sensors etc. Skills in measuring masses, weights and forces are also required. Data-handling skills such as converting displacement and time data into information on velocity or acceleration are important. Students may be encouraged to carry out project-type investigations in the motion of vehicles. There is much emphasis in the importance of graphical representations of physical phenomena in this topic. Students should learn how to plot graphs with suitable choices of scales, display experimental results in graphical forms and interpret, analyse and draw conclusions from graphical information. In particular, they should learn to interpret the physical significances of slopes, intercepts and areas in certain graphs. Students should be able to plan and interpret information from different types of data sources. Most experiments and investigations will produce a set of results which may readily be compared with those data in textbooks and handbooks. The possible learning contexts that students may experience are suggested below for reference: Performing experiments on motion and forces (e.g. using ticker-tape timers, multi-flash photography, video motion analysis, data-loggers) and a graphical analysis of the results Using light gates or motion sensors to measure speed and acceleration of a moving object 19 SECOND DRAFT Inferring the relationships among acceleration, velocity, displacement and time from a graphical analysis of empirical data for uniformly accelerated motion Using light gates or motion sensors to measure the acceleration due to gravity g Using light gates or motion sensors to determine the factors affecting acceleration Using force and motion sensors to determine the relationship among force, mass and acceleration Using multi-flash photography or video camera to analyse projectile motion or circular motion Using force sensor to determine the relationship among radius, angular speed and the centripetal force on an object moving in a circle Performing experiments on energy and momentum (e.g. colliding dynamic carts, gliders on air tracks, pucks on air tables, rolling a ball-bearing down an inclined plane, dropping a mass attached to a spring) Using light gates or motion sensors to measure the change of momentum during a collision Using light gates or motion sensors and air track to investigate the principle of conservation of linear momentum Using force sensors to measure the impulse during collision Performing experiments to show the independence of horizontal and vertical motions under the influence of gravity Performing experiments to investigate the relationships among mechanical energy, work and power Determining the output of an electric motor by measuring the rate of energy transfer Estimating work required for various tasks, such as lifting a book, stretching a spring and climbing Lantau Peak Estimating KE of various moving objects such as a speeding car, a sprinter and an air molecule Investigating the application of conservation principles in designing energy transfer devices Evaluating the design of energy transfer devices, such as household appliances, lifts, escalators and bicycles Using free-body diagrams in organising and presenting the solutions of dynamic problems Exposing students to problems that, even if a mathematical treatment is involved, have a direct relevance to their experiences (sport, transport, skating etc) in everyday life and solutions of problems related to these experiences Facilitating students to use dimension analysis to check the results of mathematical solutions 20 SECOND DRAFT Challenging students’ preconceived ideas on motion and force by posing appropriate thought-provoking questions (e.g. “zero” acceleration at the maximum height, “zero” gravitational force in space shuttle, etc.) Reinforcing students’ awareness of the power and elegance of the conservation laws by contrasting such solutions with those involving the application of Newton’s second law. Investigating motion in a plane using simulations or modelling (http://phoenix.sce.fct. unl.pt/modellus) Using the Hong Kong Ocean Park as a large laboratory to investigate laws of motion and developing numerous concepts in mechanics from a variety of experiences at the park (http://www.hk-phy.org/oceanpark/index.html) Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the importance of car safety and to be committed to safe practices in their daily life to be aware of the potential danger of falling objects from high-rises and to adopt a cautious attitude in matters concerning public safety to be aware of the environmental implications of different modes of transport and to make an effort in reducing energy consumption in daily life to accept uncertainty in the description and explanation of motions in the physical world to be open-minded in evaluating potential applications of principles in mechanics to new technology to appreciate the efforts made by scientists to find more alternative environmental friendly energy resources to appreciate that the advancement of important scientific theories (such as Newton’s laws of motion) can ultimately make huge impact on technology and society to appreciate the contributions of Galileo and Newton that revolutionised the scientific thinking of their time to appreciate the roles of science and technology in the exploration of outer-space and the efforts of mankind in the quest for the understanding of nature 21 SECOND DRAFT STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the issue of the effects of energy use on the environment the reduction of pollutants and energy consumption by restricting the use of private cars in order to protect the environment penalizing drivers and passengers who do not wear seatbelts and raising public awareness of car safety with scientific rationales how the danger of speeding and its relation to the chances of serious injury or death in car accidents can be related to the concepts of momentum and energy the use of principles in mechanics in traffic accident investigations modern transportation: the dilemma in choosing between speed and safety; the dilemma in choosing between convenience and environmental protection evaluating the technological design of modern transport (e.g. airbags in cars, tread patterns on car tires, hybrid vehicles, magnetically levitated trains) the use of technological devices including terrestrial and space vehicles (e.g. Shenzhou-5 Spacecraft) enhancement of recreational activities and sports equipment the ethical issue of dropping objects from high-rises and its potential danger as the principles of physics suggest careers that require an understanding and application of kinematics and dynamics 22 SECOND DRAFT Topic III Wave Motion (48 hours) Overview This topic examines the basic nature and properties of waves. Light and sound, in particular, are also studied in detail. Students have been familiar with examples of energy being transmitted from one place to another, together with the transfer of matter. In this topic, the concept of waves being a means of transmitting energy without transferring matter is emphasized. The foundation for describing wave motion with physics terminology is laid. Students learn the graphical representations of travelling waves. The basic properties and characteristics displayed by waves are examined; reflection, refraction, diffraction and interference are studied using simple wavefront diagrams. Students acquire specific knowledge on light in two important aspects. The characteristics of light as a part of the electromagnetic spectrum are studied. Besides that, the linear propagation of light in the absence of significant diffraction and interference effects is used to explain image formation in the domain of geometrical optics. The formation of real and virtual images using mirrors and lenses is studied with construction rules for light rays. Sound as an example of longitudinal waves is examined. Its general properties are compared with those of light waves. Students also learn about ultrasound. The general descriptions of musical notes are related to the terminology of waves. The effects of noise pollution and the importance of acoustic protection are also studied. Learning Outcomes Students should learn: a. Students should be able to: Nature and properties of waves nature of waves understand oscillations in wave motion realise waves transmitting energy without transferring matter 23 SECOND DRAFT Students should learn: Students should be able to: wave motion and propagation distinguish between transverse and longitudinal waves describe wave motion in terms of: waveform, crest, trough, compression, rarefaction, wavefront, phase, displacement, amplitude, period (T), frequency (f), wavelength (λ) and wave speed (v) present information on displacement-time and displacement-distance graphs for travelling waves determine factors affecting the speed of propagation of waves along stretched strings or springs apply f = 1/T and v = fλ to solve problems reflection and refraction account for the reflection of waves at a plane barrier/reflector/surface through Huygens’ principle determine the condition for a phase change on reflection account for the refraction of waves across a plane boundary realise refraction as a result of change in wave speeds and define refractive index in terms of speeds illustrate reflection and refraction using wavefront diagrams diffraction and interference describe the superposition of two waves qualitatively describe diffraction of waves through a narrow gap and around a corner examine relationship between the degree of diffraction and the size of the gap compared to the wavelength realise interference of waves as a property of waves identify occurrences of constructive and destructive interferences examine interference of waves from two coherent sources determine conditions for constructive and destructive interference in terms of path difference illustrate diffraction and interference of waves using wavefront diagrams 24 SECOND DRAFT Students should learn: Students should be able to: realise the characteristics of stationary waves (transverse waves only) b. Light wave nature of light use light as an example of transverse waves realise light as a part of the electromagnetic spectrum identify the range of wavelength for visible light determine the relative positions of visible light and other parts of the electromagnetic spectrum state the speed of light and electromagnetic waves in vacuum reflection of light state the law of reflection construct image formed by plane mirror graphically refraction of light state the law of refraction project path of a ray being refracted at a boundary define refractive index of a medium as n = sin i / sin r apply Snell’s law to solve problems involving refraction at a boundary between vacuum(or air) and another medium total internal reflection determine conditions for total internal reflection solve problems involving total internal reflection at a boundary between vacuum (or air) and another medium formation of images by lenses construct image formed by converging and diverging lenses graphically distinguish between real and virtual images use the equation (1/u) + (1/v) = (1/f) to solve problems for a single thin lens 25 SECOND DRAFT Students should learn: evidence for the wave nature of light Students should be able to: realise diffraction and interference as evidences for the wave nature of light formulate the interference effects for normal incidence in parallel-side and wedge-shape thin films use plane transmission grating as an interference system and apply formula d sin θ = n λ to solve problems c. Sound wave nature of sound realise sound as longitudinal waves realise requirement of a medium for the transmission of sound waves compare the general properties of sound waves and those of light waves audible frequency range determine the audible frequency range ultrasound state frequencies of ultrasound musical notes compare musical notes using pitch, loudness and quality relate frequency and amplitude with the pitch and loudness of a note respectively noise represent sound intensity level using the unit decibel identify effects of noise pollution and the importance of acoustic protection Suggested Learning and Teaching Activities Students should develop experimental skills in the study of vibration and waves through various physical models. They need to develop the skills for interpreting indirect measurements and demonstrations of wave motion through the displays on the CRO or the computer. They should appreciate that many scientific evidences are obtained through indirect measurement coupled with logical deduction. They should also be aware that various theoretical models are used in the study of physics; for example, the ray model is 26 SECOND DRAFT used in geometrical optics for image formation and the wave model of light is used to explain phenomena like diffraction and interference. Through the study of the physics of musical notes, students should develop the understanding that most everyday experiences are explicable by scientific concepts. The possible learning contexts that students may experience are suggested below for reference: Investigating properties of waves generated in springs and ripple tanks Investigating factors affecting the speed of transverse progressive waves along a slinky spring Determining the speed of a water wave in a ripple tank or a wave pulse travelling along a stretched spring or string Illustrating phase change on reflection using a slinky spring Demonstrating the superposition of transverse waves on a slinky spring Using CRO waveform demonstrations to show the superposition of waves Drawing the resultant wave when two waves interfere by using the principle of superposition Estimating the wavelength of light by using double slit or plane diffraction grating Estimating the wavelength of microwave by using double slit Demonstrating interference patterns in soap film Determining the effects of wavelength, slit separation or screen distance on an interference pattern in an experiment by using double slit Measuring the focal lengths of lenses Locating real and virtual images in lenses by using ray boxes and ray tracing Using ray diagrams to predict the nature and position of an image in an optical device Searching information on the development of physics of light Discussing some everyday uses and effects of electromagnetic radiation Using computer simulations to observe and investigate the properties of waves Investigating the relationship between the frequency and wavelength of a sound wave Carrying out an experiment to verify Snell’s law Determining the refractive index of glass or Perspex Determining the conditions for total internal reflection to occur Constructing, testing and refining a prototype of an optical instrument Identifying the differences between sounds in terms of loudness, pitch and quality Facilitating students to use dimension analysis to check results of mathematical solutions 27 SECOND DRAFT Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to appreciate the need to make more use of some environmental friendly energy resources such as solar and tidal-wave energy to be aware that science has its limitations and cannot always provide clear-cut solutions; the advancement of science also requires perseverance, openness and scepticism, as demonstrated in the different interpretations on the nature of light in the history of physics over the past centuries to appreciate that the advancement of important scientific theories (such as those related to the study of light) is the fruits of the hard work of generations of scientists who devoted themselves to scientific investigations by applying their intelligence, knowledge and skills to be aware of the potential health hazards of a prolonged exposure to extremely noisy environment and to make an effort to reduce noise-related disturbances to neighbours to be aware of the importance of the proper use of microwave ovens and to be committed to safe practices in their daily life STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: controversial issues about the effects of microwave radiation on the health of the general public through the use of mobile phones the biological effects of increased ultra-violet radiation from the sun on the human body as a result of the depletion of the atmospheric ozone layer by artificial pollutants the problem of noise pollution in the local context the impact on the society as a result of the scientific discovery of electromagnetic waves and the technological advancements in the area of telecommunication how major breakthroughs in scientific and technological development that eventually affect society are associated with new understanding of fundamental physics as traced out by the study of light in the history of science how technological advancements can provide impetus for scientific investigations as 28 SECOND DRAFT demonstrated in the invention and development of the microscope, telescope and X-ray diffraction etc., with these scientific investigations in turn shedding light on our own origin and the position of mankind in the universe 29 SECOND DRAFT Topic IV Electricity and Magnetism (56 hours) Overview This topic examines the basic principles of electricity and magnetism. The abstract concept of an electric field is introduced through its relationship with the electrostatic force. The inter-relationships among voltage, current, resistance, charge, energy and power are examined and the foundation for basic circuitry is laid. Electricity is the main energy source in homes and electrical appliances have become an integral part of daily life. The practical use of electricity in households is studied. Particular attention is paid to the safety aspects of domestic electricity. The concept of magnetic field is applied to the study of electromagnetism. The magnetic effects of electric current and some simple magnetic field patterns are studied. Students also learn the factors that affect the strength of an electromagnet. The magnetic force is produced when a current-carrying conductor is placed in a magnetic field. An electric motor requires the supply of electric current to the coil in a magnetic field to produce a turning force causing it to rotate. The general principles of electromagnetic induction are introduced. Electrical energy can be generated when there is relative motion between a conductor and a magnetic field. Generators reverse the process in motors to convert mechanical energy into electrical energy. The operation of simple d.c. and a.c. generators are studied. Students learn how a.c. voltages can be stepped up or down with transformers. The system by which electrical energy is transmitted over great distances to our home is studied. Learning Outcomes Students should learn: a. Students should be able to: Electrostatics electric charges examine experimental evidences for two kinds of charges in nature realise the attraction and repulsion between charges define Coulomb’s law 30 SECOND DRAFT Students should learn: Students should be able to: use coulomb as a unit of charge interpret charging in terms of electron transfer b. electric field realise the existence of an electric field around a point charge represent electric field using lines of force describe the electric field around a point charge and between parallel charged plates explain how charges interact using electric field consider electric field strength as force per unit charge solve problems involving electric field strength around a point charge and between parallel charged plates draw analogy between electric field and gravitational field electric potential define potential difference between two points solve problems involving potentials in the fields of a point charge and parallel plates recognise electric field strength as the negative gradient of potential use volt as a unit of electric potential Circuits and domestic electricity electric current realise an electric current as a flow of electric charges realise the convention for the direction of electric current use ampere as a unit of current estimate electron drift velocity in a metal using the general flow equation I = nAvQ electrical energy and electromotive force describe the energy transformations in electric circuits define electromotive force (e.m.f.) of a source recognise potential difference (p.d.) between two points as the energy being converted from electrical potential 31 SECOND DRAFT Students should learn: Students should be able to: energy to other forms per unit charge passing between the points outside the source distinguish between e.m.f. of a source and terminal voltage across the source resistance recognise the variation of current with applied p.d. in various conductors and circuit elements (metals, electrolytes, thermistors and diodes) define resistance R = V/I recognise Ohm’s law as a special case of resistance behaviour use ohm as a unit of resistance determine the factors affecting the resistance of a wire and define its resistivity realise the effects of temperature on resistance of metals and semiconductors apply formula V = IR and Kirchhoff’s first law to solve problems series and parallel circuits compare series and parallel circuits in terms of voltage across the components of each circuit and the current through them recognise the resistance combinations in series and parallel circuits R = R1 + R2 + ….. for resistors connected in series 1 1 1 = + + ..... for resistors connected in parallel R R1 R2 simple circuits determine I, V and R in simple circuits examine the effects of resistance of ammeters, voltmeters and internal resistance of cells in simple circuits 32 SECOND DRAFT Students should learn: c. Students should be able to: electrical power determine the heating effect when a current passes through a conductor apply formula P = VI to solve problems domestic electricity determine power rating of electrical appliances use kilowatt-hour (kWh) as a unit of electrical energy calculate the costs of running various electrical appliances recognise household wiring and the safety aspects of domestic electricity determine the operating current for electrical appliances and the choice of power cable and fuse Electromagnetism magnetic force and magnetic field realise the attraction and repulsion between magnetic poles examine the existence of magnetic field in the region around a magnet represent magnetic field using field lines describe the behaviour of a compass in a magnetic field magnetic effect of electric current realise the existence of magnetic field due to moving charges and electric currents describe the magnetic field patterns associated with currents through a long straight wire, a circular coil and a long solenoid use the formulae B = µ0I/2πr and B = µ0NI/l to represent the magnetic fields around a long straight wire, and inside a long solenoid, carrying current determine the factors affecting the strength of an electromagnet 33 SECOND DRAFT Students should learn: Students should be able to: current-carrying conductor in magnetic field realise the existence of a force on a current-carrying conductor in a magnetic field and determine relative directions of force, field and current determine the factors affecting the force on a current-carrying conductor in a magnetic field and represent the force on it by the formula F = BIl sinθ define ampere by measuring the force between currents in long straight parallel conductors recognise the turning effect on a current-carrying coil in a magnetic field describe the operating principles of a simple d.c. or a.c. motor Hall effect define the force on a moving charge in a magnetic field as F = BQv sinθ derive Hall voltage VH = BI/nQt measure magnetic fields using Hall probe and search coil electromagnetic induction recognise induced e.m.f resulting from a moving conductor in a steady magnetic field and a stationary conductor in a changing field define magnetic flux interpret magnetic field B as magnetic flux density apply Lenz’s law to identify the direction of induced current in a closed circuit apply Faraday’s Law to calculate the average induced e.m.f. understand the operating principles of simple d.c. and a.c. generators recognise the occurrence and practical uses of eddy currents alternating currents (a.c.) examine the mean heating effect in a pure resistance when a sinusoidal alternating current is passing through it 34 SECOND DRAFT Students should learn: Students should be able to: recognise the r.m.s. and peak values of a sinusoidal a.c. transformer describe the operating principle of a simple transformer relate the voltage ratio to turns ratio by by the formula VP N P and apply the relationship to solve problems = VS N S determine the efficiency of a transformer examine methods for improving the efficiency of a transformer high voltage transmission of electrical energy describe the advantage of transmission of electrical energy with a.c. at high voltages recognise various stages of stepping up and down of the voltage in a grid system for power transmission Suggested Learning and Teaching Activities Students should develop experimental skills in connecting up circuits. They are required to perform electrical measurements using various types of equipments, such as ammeters, voltmeters, multi-meters, joulemeter, CRO and data-logging probes. Students should acquire the skills in performing experiments to study, demonstrate and explore concepts of physics, such as electric fields, magnetic fields and electromagnetic induction. Students can gain practical experiences related to design and engineering in building physical models, such as electric motors and generators. It should, however, be noted that all experiments involving the mains power supply and EHT supply must be carefully planned to avoid the possibility of an electric shock. Handling apparatus properly and safely is a very basic practical skill of great importance. The possible learning contexts that students may experience are suggested below for reference: Showing the nature of attraction and repulsion using simple electrostatic generation and testing equipment Investigating the nature of electric field surrounding charges and between parallel plates 35 SECOND DRAFT Plotting electric field lines by using simple measurement of equipotentials in the field Measuring current, e.m.f., and potential difference around the circuit by using appropriate meters and calculating the resistance of any unknown resistors Verifying Ohm’s law by finding the relationship between p.d. across a resistor and current passing through it Determining factors affecting the resistance of a resistor Comparing the changing resistance of ohmic devices, non-ohmic devices and semiconductors Designing and constructing an electric circuit to perform a simple function Analysing real or simulated circuits to identify faults and suggesting appropriate changes Comparing the efficiency of various electrical devices and suggesting ways of improving efficiency Measuring magnetic field strength by using simple current balance, search coil and Hall probe Performing demonstrations to show the relative directions of motion, force and field in electromagnetic devices Disassembling loudspeakers to determine the functions of individual components Investigating the magnetic fields around electric currents (e.g. around a long straight wire, at the centre of a coil, inside and around a slinky solenoid and inside a solenoid) Constructing electric motor kits and generator kits Measuring the transformation of voltages under step-up or step-down transformers Estimating the e/m ratio by measuring the radius of curvature in a magnetic field of known strength Planning and selecting appropriate equipment or resources to demonstrate the generation of an alternating current Using computer simulations to observe and investigate the electric field and magnetic field Facilitating students to use dimension analysis to check results of mathematical solutions Identifying hazardous situations and safety precautions in everyday uses of electrical appliances Investigating the need for and the functioning of circuit breakers in household circuits Reading articles on possible hazardous effects on residents living near high voltage transmission cables Searching information on the uses of resistors in common appliances (e.g. volume control, light dimmer switch) 36 SECOND DRAFT Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to appreciate that the application of scientific knowledge can produce useful practical products and transform the daily life of human beings as demonstrated in the numerous inventions related to electricity to be aware of the importance of technological utilities such as electricity, to the modern society and the effects on modern life if these utilities are not available for whatever reason to be aware of the need to save electrical energy for reasons of economy as well as environmental protection to be committed to the wise use of natural resources and to develop a sense of shared responsibility for a sustainable development of mankind to be aware of the danger of electric shocks and the fire risk associated with improper use of electricity, and develop good habits in using domestic electricity STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the effects on health as a result of living near high power transmission cables the potential hazards of the mains supply versus the conveniences of ‘plug-in’ energy and automation it offers to society the environmental implications and recent developments of the electric car as an alternative to the traditional fossil-fuel car; the role of the government on such issues the views of some environmentalists on the necessity to return to a more primitive or natural life-style with minimum reliance on technology 37 SECOND DRAFT Topic V Radioactivity and Nuclear Energy (16 hours) Overview In this topic, nuclear processes are examined. Ionising radiation is very useful in industrial and medical fields but at the same time it is hazardous to us. Nuclear radiation comes from natural and artificial sources. It is essential for students to understand the origin of radioactivity, the nature and the properties of radiation. Students should also learn simple methods to detect radiation and identify major sources of background radiation in our natural environment. Simple numerical problems involving half-lives are performed in order to understand the long-term effects of some radioactive sources. The potential hazards of ionizing radiation are studied scientifically and in a balanced way by bringing in the concept of dosage. In the atomic model, the basic structure of a nuclide is represented by a symbolic notation. Students learn the concepts of isotopes. They are also introduced to fission and fusion, nature’s most powerful energy sources. Learning Outcomes Students should learn: a. Students should be able to: Radiation and Radioactivity X-rays realise X-rays as ionizing electromagnetic radiations of short wavelengths with high penetrating power realise the emission of X-rays when fast electrons hit a heavy metal target α, β and γ radiation describe the origin and nature of α, β and γ radiation compare α, β and γ radiation in terms of their penetrating power, ranges, ionizing power, behaviour in electric field and magnetic field, and cloud chamber tracks 38 SECOND DRAFT Students should learn: b. Students should be able to: radioactive decay realise the occurrence of radioactive decay in unstable nuclides demonstrate the random nature of radioactive decay determine the proportional relationship between the activity of a sample and the number of undecayed nuclei define half-life realise the relationship between decay constant in the exponential law of decay N = Noe-kt and the half-life determine the half-life of a radioisotope from its decay graph or from numerical data solve problems involving half-life detection of radiation detect radiation with photographic film and GM counter measure radiation in terms of count rate using a GM counter radiation safety identify major sources of background radiation use the unit sievert to represent radiation dose describe potential hazards of ionizing radiation and the ways to minimize the radiation dose absorbed suggest safety precautions in handling radioactive sources Atomic model atomic structure realise the structure of a typical atom define atomic number and mass number use symbolic notations to represent nuclides isotopes and radioactive transmutation define isotope recognise the existence of radioactive isotopes in some elements represent radioactive transmutations in α, β and γ decays using equations 39 SECOND DRAFT Students should learn: c. Students should be able to: Nuclear energy nuclear fission recognise the release of energy in nuclear fission describe the principle of the fission reactor and nuclear chain reaction state the roles of fuel, moderator, coolant and control rods nuclear fusion realise release of energy in nuclear fusion realise nuclear fusion as the source of solar energy Suggested Learning and Teaching Activities Students must be properly warned about the potential danger of radioactive sources. The regulations regarding the use of radioactivity for school experiments must be strictly observed. Although students are not allowed to handle sealed sources, they can acquire experimental skills by participating in the use of the Geiger-Muller counter in an investigation of the background radiation. Fire alarms making use of weak sources may also be used in student experiments under teachers’ supervision. However, proper procedures should be adopted and precautions should be taken to avoid accidental detachment of the source from the device. Analytic skills are often required to draw meaningful conclusions from the results of radioactive experiments that inevitably involve background radiation. The possible learning contexts that students may experience are suggested below for reference: Measuring background radiation by using a GM counter Showing the activity of a sample to be proportional to the remaining number of unstable nuclides by using simulation or decay analogy with dice Demonstrating the random variation of count rate by using a GM counter and a source Identifying sources of natural radiations and investigating why exposure to natural radiation is increased for airline crews and passengers Determining the factors leading to an increase in the concentration of radon in high-rises 40 SECOND DRAFT Reading the specification for commercial products containing radiation such as smoke detectors Determining risks and assessing benefits of using nuclear radiations in medical diagnosis Suggesting ways of disposing radioactive wastes Estimating the half-life from a graph of activity plotted against time Searching information on the use of radioactive dating, radioactive tracers, food irradiation and product sterilisation Searching information on the ethics of using nuclear weapons Comparing the relative costs and benefits from the use of nuclear reactors with other methods of producing electrical power Searching information on nuclear accidents and reporting a case study on nuclear accidents Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the usefulness of models and theories in physics as shown in the atomic model and appreciate the wonders of nature to be aware of the need to use natural resources judiciously to ensure the quality of life for future generations to be aware of the benefits and disadvantages of nuclear energy resources when compared to fossil fuels to be aware of the views of society on the use of radiation: the useful applications of radiation in research, medicine, agriculture and industry are set against its potential hazards to be aware of different points of view in society on controversial issues and appreciate the need to respect others’ points of view even in disagreement; and to adopt a scientific attitude when facing controversial issues, such as debates on the use of nuclear energy STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: 41 SECOND DRAFT the use of nuclear power; the complex nature of the effects caused by developments in science and technology in our society the moral issue of using various mass destruction weapons in wars the political issue of nuclear deterrents the roles and responsibilities of scientists and the related ethics in releasing the power of nature as demonstrated in the developments of nuclear power stocking and testing of nuclear weapons the use of fission reactors and the related problems such as disposal of radioactive wastes and leakage of radiation 42 SECOND DRAFT Elective part (Total 54 hours, any 2 out of 4) Topic VI Astronomy and Space Science (27 hours) Overview Astronomy is the earliest science emerged in history. The methods of measurement and the ways of thinking developed by early astronomers laid the foundation of scientific methods which influenced the development of science for centuries. The quest for a perfect model of the universe in the Renaissance eventually led to the discovery of Newton's law of universal gravitation and the laws of motion. This had profound influence on the subsequent rapid development in physics. Using physical laws in mathematical form to predict natural phenomena, and verifying these predictions with careful observation and experimentation, like what Newton and other scientists did some 300 years ago, has become the paradigm of modern physics research. Physics has become the cornerstone of modern astronomy, it has revolutionised our concepts of the universe and the existence of mankind. Modern development of space science, such as the launch of spacecraft and artificial satellites, still relies on Newtonian physics. In this topic, students have the chance to learn principles and scientific methods underpinning physics, as well as to appreciate the interplay between physics and astronomy in history, through studying various phenomena in astronomy and space science. Students are first given a brief introduction on the phenomena of the universe as seen in different scales of space. Students are also encouraged to perform simple astronomical observation and measurement similar to those achieved by famous astronomers in history. Through these processes, they can acquire experimental skills, and be more familiar with the concept of tolerance in measurement. A brief historic review on Ptolemy’s geocentric model and Copernicus’ heliocentric model of the universe serves to stimulate students to think critically on how scientific hypotheses were built on the basis of observation. Concepts of uniform circular motion, including centripetal acceleration and its relation with simple harmonic motion, are introduced. Kepler’s third law and Newton's law of gravitation are introduced with examples of astronomy. Kepler’s third law for circular orbits is derived from the law of gravitation. Besides the motion of planets, moons and satellites, latest astronomical discoveries such as binary stars, extrasolar planets and supermassive black holes can also serve as examples to illustrate the applications of these laws. 43 SECOND DRAFT The concepts of mass and weight are introduced. Feeling weightlessness in a spacecraft orbiting the earth is explained in terms of the fact that acceleration under gravity is independent of mass. The expression for gravitational potential energy is derived from the law of gravitation and work-energy theorem. Motions of artificial satellites are explained by the conservation of mechanical energy in their orbits. The meaning of the escape velocity, together with its implication on the launching of a rocket, is introduced. In the last part of this topic, students are exposed to modern astronomical discoveries, including the basic properties and classification of stars, stellar evolution, exotic stars like white dwarf, neutron star and black hole, and expansion of the universe. As only a simple, heuristic and qualitative understanding of these topics is expected, students are encouraged to learn actively by reading popular science articles and astronomical news. This serves to enhance students' self-learning attitude. Oral or written presentation of what they have learnt may serve to improve their communication skills. Learning Outcomes Students should learn: a. Students should be able to: The universe as seen in different scales structure of the universe use the “Powers of Ten” approach to describe the essential features of the universe as seen in different space scales describe the universe using basic terminology in astronomy, such as planet, star, cluster, nebula, galaxy and cluster of galaxy the sky as seen from the earth use the celestial sphere as a model to describe the apparent motions of celestial bodies describe the sky as seen from different latitudes on earth describe the daily motion of the celestial sphere, the yearly motion of the sun, and seasonal changes 44 SECOND DRAFT Students should learn: b. Astronomy through history historical development of the models of the universe c. Students should be able to: describe some contributions of the ancient Greeks on astronomy, including i) the measurement of the radius of earth and the distance of the moon ii) creating a geocentric model of the universe, and the use of epicycle and deferent to explain the retrograde motion of planets describe why Copernicus’ heliocentric model is better than Ptolemy’s geocentric model in explaining the motion of planets describe Galileo’s astronomical discoveries and their implications describe planetary motion through applying Kepler’s laws Newton’s law of gravitation Newton’s law of gravitation and orbital motions state Newton’s law of gravitation F = GMm r2 apply Newton’s law of gravitation to celestial objects in circular orbits. analyze the motions of celestial objects by using Kepler’s 4πr 3 third law T 2 = GM state Kepler’s third law for elliptical orbits T 2 = 4πa 3 , GM and apply the law to comets and spacecraft travelling to outer planets. weight and weightlessness understand weightlessness in a spacecraft as a result of acceleration under gravity being independent of mass 45 SECOND DRAFT Students should learn: conservation of energy and the motions of celestial objects d. Students should be able to: understand the meaning of the expression U = − GMm r for gravitational potential energy use conservation of mechanical energy to describe the orbital motions of celestial objects and orbiting spacecraft. use the concept of escape velocity to determine whether an object can leave a planet permanently Stars and the universe stellar luminosity and classification understand the meaning of stellar magnitude and distinguish between apparent magnitude m and absolute magnitude M describe the shape of blackbody radiation curves, and the relation of colour to the surface temperature of stars describe the relation of luminosity to the surface temperature and radius of a star describe briefly the spectral classes: O B A F G K M and their relation to surface temperature of a star describe the basic properties of different kinds of stars in the Hertzsprung-Russell diagram stellar evolution describe briefly the evolution of high-mass stars and low -mass stars. describe briefly the properties of nebulae, white dwarfs, supernovae, neutron stars and black holes Doppler effect understand Doppler effect and use the formula ∆f v r ≈ f c to determine the radial velocity of a celestial object use radial velocity curve to determine the orbital radius, speed, and period of a celestial object in circular orbital motion 46 SECOND DRAFT Students should learn: expansion of the universe Students should be able to: describe the receding of distant galaxies using Hubble’s law ( v = Hd ) understand Hubble’s law as the result of expansion of the universe describe briefly Big Bang as the beginning of the universe understand cosmic background radiation as an evidence of the Big Bang Suggested Learning and Teaching Activities Students should develop basic skills in astronomical observation. Observation can capture students’ imagination and enhance their interest in understanding the mystery of the universe. It also serves to train their practical and scientific investigation skills. Students may use naked eye to observe the apparent motion of celestial objects in the sky, and use telescopes/binoculars to study the surface features of the moon, planets and deep sky objects. Simple application of imaging devices such as digital camera or CCD is useful. Project-based investigation may also enhance students’ involvement and interest. Space museum, universities, and many local organisations have equipment and expertise on amateur astronomical observation. They would welcome school visits and provide training for enthusiastic teachers. Data handling skills such as converting radial velocity data into information of orbital motion is important. Due to the limitation on equipment, time, weather condition, and light pollution, however, it is quite difficult for students to obtain useful observation data for analysis. While real observation provides a vivid learning experience for students and should be retained for a complete topic in astronomy, animation may be used as a complement to strengthen their understanding of the analytical contents, and train their data acquisition and handling skills. Standard animation tools, a huge source of photos and videos are available in the NASA website. Software such as Motion Video Analysis may help students use these resources to perform useful analysis. Connection of the analysis results with curriculum contents and modern astronomical discoveries should be emphasized. This would help students appreciate the importance of the physics principles they learnt, and realise physics is an ever growing subject that modern discoveries often emerge from the 47 SECOND DRAFT solid foundation laid previously. Apart from the acquisition of practical and analytical skills, students may take learning advanced topics (such as evolution of stars and cosmology) and new astronomical discoveries as a valuable opportunity to broaden their perspectives in modern science. Students should not aim at a comprehensive understanding of these topics, but rather, they should try to gain a simple, heuristic and qualitative glimpse of the wonders of the universe, as well as to appreciate the effort that scientists have made leading to these important discoveries. A huge source of astronomy education resources/articles is available on the web. Students may develop self-learning attitude through studying these materials, and polish their communication skills in sharing what they have learnt with their classmates. The possible learning contexts that students may experience are suggested below for reference: Observation of astronomical phenomena Naked eye observation of stars, recognizing the constellations, and the apparent motion of celestial objects in the sky Naked eye observation of meteor showers Observing the surface of the moon with a small telescope Observing a lunar eclipse and/or solar eclipse with a small telescope. Observing the features of major planets with a small telescope, like the belts and satellites of Jupiter, the phases of Venus, the polar caps of Mars, the ring of Saturn, etc. Observing special astronomical events such as opposition of Mars, transit of Venus over the sun with a small telescope Observing bright comets with a small telescope Observing binary stars and variable stars with a small telescope Observing deep sky objects with a small telescope Observing features of the sun (sunspots, granules, etc.) with a small telescope Recording the position and/or features of the above objects with a digital camera or an astronomical CCD Possible learning activities Use a transparent plastic bowl to trace the path of daily motion of the sun on the celestial sphere. Students can examine the paths in different seasons to understand how the altitudes of the sun and the duration of sunshine vary throughout the year. (Reference: http://www.ied.edu.hk/apfslt/issue_2/si/article4/a4_1.htm) Measuring the radius of the earth and the distance of the moon from the earth using 48 SECOND DRAFT the methods developed by ancient Greek scholars: Students may use a digital camera to obtain photos of the full moon and moon during eclipse. They can estimate from the photos the size of the earth shadow relative to that of the moon and hence calculate the distance to the moon. The activity let students appreciate the intelligence of ancient people in using simple methods to obtain important results, and be more familiar with the concept of tolerance in scientific measurement. (Reference: http://www.hk-phy.org/astro/tcs.zip) Recording the position of Galilean satellites of Jupiter: Students may use the size of Jupiter as the reference length to estimate the period and orbital radius of the satellites. To avoid technical difficulties in observation, students may use the Solar System Stimulator provided by NASA (http://space.jpl.nasa.gov/) and Motion Video Analysis Software (http://www.hk-phy.org/mvas) to perform a virtual analysis of the satellites’ motion on a computer. They can also verify Kepler’s third law in this case. (Reference: http://www.hk-phy.org/astro/tcs.zip) Recording the position of planets/asteroids in the sky by using a digital camera over a few months: Students may use a star map to estimate the coordinates of the planets/ asteroids and use standard astronomical software to analyze the orbit of the planet. Mapping of sunspots: Students may use a small telescope (with appropriate solar filter) to observe the sun and map the sunspots in a period of time. From this they can realise the rotation of the sun and evolution of sunspots. Recording the relative sunspot number over a period of time may also reveal the change in solar activity. Studying the physics of Shenzhou V manned spacecraft: The historic journey of Shenzhou V have many interesting physics phenomena that are understandable by secondary school students, for example, the thrust and acceleration of the rocket during its launch, the orbital motion around the earth, the weightless condition in the spacecraft, the deceleration and return of the returning capsule, the effect of air resistance on the return capsule, communication problem when returning to the atmosphere, etc. Analysis of spacecraft data provides lively illustration of physics principles. Motion video analysis may also be useful in studying the launching motion. Studying orbital data of artificial satellites also provides interesting illustration of Newtonian mechanics: Students may also check the satellite pass over time to actually observe the satellite in the evening sky. Using a spectrograph and suitable filter to observe the spectrum of the sun: Some prominent spectral absorption lines can be observed without much difficulty. Studying radial velocity curves in celestial systems like stars with extrasolar planets, 49 SECOND DRAFT black holes in binaries, may serve expose students to the latest advances in astronomy. Based on the information extracted from the curves, students can use Kepler's third law to deduce the mass and orbital radius of the unknown companion in binary systems, and recognise the important implications of these discoveries on the existence on exotic celestial objects and extraterrestrial life. Studying articles about the latest astronomy discoveries can promote students’ interest in modern science and strengthen their self-learning ability. Oral or written presentation in class is encouraged. Visiting Hong Kong Space Museum: Students may be divided into groups, each group is responsible for gathering information for a particular astronomy topic in the exhibition hall of the museum. Each group can give a short presentation in class. Local organisations, observatories and museums Hong Kong Space Museum (http://www.lcsd.gov.hk/CE/Museum/Space/e_index.htm) Ho Koon NEAC (http://www.hokoon.edu.hk/) TNL Centre, The Chinese University of Hong Kong (http://www.cuhk.edu.hk/ccc/tnlcenter/) Sky Observers’ Association (Hong Kong) (http://www.skyobserver.org/) Hong Kong Astronomical Society (http://www.hkas.org.hk/links/index.php) Space Observers Hong Kong (http://www.sohk.org.hk/) Taipei Astronomical Museum (http://www.tam.gov.tw/) Educational websites that provide useful resources for activities Astronomy picture of the day (http://antwrp.gsfc.nasa.gov/apod/astropix.html) NASA homepage (http://www.nasa.gov/home/index.html?skipIntro=1) The Hubble Space News Center (http://hubblesite.org/newscenter/) Chandra X-ray Observatories News (http://chandra.nasa.gov/) Jet Propulsion Laboratory (http://www.jpl.nasa.gov/index.cfm) NASA Earth Observatory (http://earthobservatory.nasa.gov/) Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to appreciate the wonders of deep space and understand the position of human beings in the universe 50 SECOND DRAFT to appreciate astronomy as a science which is concerned with vast space and time, and the ultimate quest for the beginning of the universe and life to appreciate how careful observation, experimentation and analysis often lead to major discoveries in science that revolutionise our concepts of nature to appreciate physics as an ever growing subject in which new discoveries are often made on the solid foundation that was laid previously to appreciate the intelligence of famous scientists in history and their profound contribution towards our understanding of the universe and the existence of mankind to accept uncertainty in the description and explanation of physical phenomena to accept the uncertainty in measurement and observation but still be able to draw meaningful conclusions from available data and information to be able to get a simple and heuristic glimpse of modern advancements in science even though a comprehensive understanding of these advanced topics is beyond the ability of ordinary people to recognise the importance of life-long learning in our rapidly changing knowledge-based society and be committed to self-learning to appreciate the roles of science and technology in the exploration of space and to appreciate the efforts of mankind in the quest for understanding nature to become aware of daily phenomena and their scientific explanations STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the studies of astronomy have stimulated the development of modern science which has eventually changed our ways of thinking and living the interplay between technological development, the advance of modern science and our lives the effects of astronomical phenomena on our lives (e.g. solar activity maximum affects communication and power supply on earth) disasters that may come from outer space and our reactions to them (e.g. a big meteor impact may cause massive extinction of lives on earth) the applications of modern technologies in space science, including artificial satellites and spacecraft the exploration of planets in the solar system has led us to rethink some environmental 51 SECOND DRAFT problems on earth (e.g. the runaway greenhouse effect of Venus may be compared with the global warming on earth) the implications of the advancement of space technology and its impact on the society (e.g. Shenzhou V manned spacecraft) 52 SECOND DRAFT Topic VII Atomic World (27 hours) Overview The nature of the smallest particles making up of all matter has been a topic of vigorous debates among scientists, starting from ancient time through the exciting years in the first few decades of the 20th century to the present. Classical physics deals mainly with particles and waves, as two distinct entities. Substances are made of very tiny particles. Waves, such as those encountered in visible light, sound and heat radiations, behave very differently from particles. At the end of the 19th century, particles and waves were thought to be very different and could not be associated with each other. When scientists looked closer and closer to the nature of substances, contradictory phenomena that confused scientists appeared. Classical concepts in Mechanics and Electromagnetism cannot successfully explain the phenomena observed in atoms, not to mention their failure in explaining the very existence of atoms. Following historical developments, we study the structure of an atom and the nature of light and electrons. Discoveries and experiments revealed that both light, the wave nature of which is well known, also shows particle properties, and electrons, the particle nature of which is well known, also show wave properties. In this elective topic, students shall learn about the development of the atomic model, the Bohr’s atomic model of hydrogen, energy levels of atom, the characteristics of line spectra, photo-electric effect, the particle behaviour of light and the wave nature of electrons, i.e., the wave-particle duality. Through the learning of these physical concepts and phenomena, students will be introduced the quantum view of our microscopic world and be aware of the difference between classical and modern views of our physical world. Students are also expected to appreciate the evidence-based, developmental and falsifiable nature of science. Advancements in modern physics have led to many applications and the rapid development in material science in recent years. This elective includes a brief introduction to nanotechnology, with a discussion on the advantage and use of transmission electron microscopes (TEM), scanning tunnelling microscopes (STM), atomic force microscopes (AFM), and some potential applications of nano-structures. Nanotechnologies have been around for hundreds of years, although the underlying physics was not known until the 20th century. For example, nano-sized particles of gold and silver have been used as coloured pigments in stained glass since the 10th century. With better 53 SECOND DRAFT understanding of the basic principles, more applications have been found in recent years. These applications include the potential use of nano-wires and nano-tubes as building materials and as key components in electronics and display. Nano-particles are used in suntan lotions and cosmetics, to absorb and reflect ultra-violet rays. Tiny particles of titanium dioxide, for example, can be layered onto glass to make self-cleaning windows As in any newly developed area, very little is known, for example, about the potential effects of free nano-particles and nano-tubes on the environment. They could possibly cause hazards to our health and might lead to health concerns. Students are, therefore, expected to be aware of the potential hazards, and issues of risks and safety concerns to our life and society in using nanotechnologies. In studying this elective topic, students are expected to have the basic knowledge of force and motion, and waves. Knowledge of electromagnetic forces, electromagnetic induction and electromagnetic spectrum are also required. Learning Outcomes Students should learn: a. Rutherford’s atomic model the structure of atom b. Students should be able to: describe Rutherford’s construction of an atomic model consisting of a nucleus and electrons distinguish between atomic mass number and atomic number understand the limitations of Rutherford’s atomic model in accounting for the motion of electrons around the nucleus by the view of classical mechanics recognise the importance of scattering experiments used in the discovery of the structure of atom and its impacts on the searching of new particles Photoelectric effect evidence for light quanta describe photoelectric experiment and the results explain to what extent the results can be accounted for 54 SECOND DRAFT Students should learn: Students should be able to: by the wave model and by the photon model of light describe how the intensity is related to the number of photons Einstein’s Interpretation of photoelectric effect and photoelectric equation state the photon energy E = hf understand Einstein’s photoelectric equation 1 2 hf − φ = me v max 2 carry out calculations using the above relationships c. Bohr’s atomic model of hydrogen line spectra recognise the special features of the line spectra of hydrogen atom and other monatomic gases explain spectral lines in terms of difference in energies recognise that the energy of a hydrogen atom can only take on certain values recognise line spectra as evidence of energy levels of atom Bohr’s model of the hydrogen atom state the postulates that define Bohr’s model of hydrogen atom recognise the ‘quantum’ and ‘classical’ aspects in the postulates of Bohr’s atomic model of hydrogen state the quantization of angular momentum of an nh electron around the nucleus as me vr = , where 2π n=1,2,3… is the quantum number labelling the nth Bohr orbit of the electron realise the equation for the energy level of electron in a 4 hydrogen atom as Etot = − 12 me2e 2 , [where Etot is the n 8h ε o electron’s total energy, n = 1,2,3… is the quantum number labelling the nth Bohr orbit of the electron, me 55 SECOND DRAFT Students should learn: Students should be able to: is the mass of an electron, e is the charge of an electron, h is the Planck’s constant and εo is the permittivity of vacuum] (derivation is not required) realise the use of electron-volt (eV) as a unit of energy understand ionization and excitation energies of an electron in an atom carry out calculations using the above relationship The interpretation of line spectra derive, by using Bohr’s equation of electron energy and 3 2 2 2 E=hf, the expression λa→b = 8h εo4c a2 b 2 for the mee a − b wavelength of photon emitted or absorbed when an electron makes a transition from one energy level to another [where a and b label the two energy levels involved in the transition] interpret line spectra by the use of Bohr’s equation of electron energy carry out calculations using the above relationship d. Particles or Waves recognise the wave-particle duality of electrons and light describe evidences of electrons and light exhibiting both wave and particle properties relate the wave and particle properties of electrons using qualitative treatment of de Broglie formula, h λ= p realise wave-particle duality is a common phenomenon in the microscopic world carry out calculations using the above relationship 56 SECOND DRAFT Students should learn: e. Students should be able to: Probing into nano scale physical properties of materials in nano size recognise nano is a unit of length which means 10-9 recognise materials often exhibits different physical properties when it is in bulk form and in nano size recognise nano materials can be in various forms, such as nano wires, nano tubes and nano particles, and the special properties commonly found in nano materials the seeing and manipulating at nano scale recognise the limit of optical microscope and the use of electron microscope in seeing substances in nano scale understand briefly the principle of operation of the transmission electron microscope (TEM) understand the advantage of electron microscopes (e.g. transmission electron microscope), in terms of high resolution as indicated by the wavelength λ of electrons estimate the anode voltage of an electron microscope needed to produce wavelengths of the order of the size of an atom discuss briefly on the analogy of using electric and magnetic fields in electron microscopes as that of lenses in optical microscopes understand briefly the principles of operation of scanning tunnelling microscope (STM) and atomic force microscope (AFM) in seeing and manipulating particles in nano scale (details of the tunnelling effect not required) recognise the nanoscience phenomena in Nature such as the Lotus Effect and its use in commercial products recognise the recent development and applications of nanotechnology in various areas related to our daily life be aware of the potential hazards, and issues of risks and safety concerns to our life and society in using nanotechnologies 57 SECOND DRAFT Suggested Learning and Teaching Activities Students may follow the history of the discovery of atom, i.e. a historical approach, in learning the elective topic. Students should develop knowledge of the structure of atom, energy level of electron and quantized energy of light. The work of various physicists such as Rutherford, Bohr, and Einstein, on the search of the nature of atoms and light should also be recognised. Students should aware of the importance of co-operation among scientists on investigations and discovery of the nature. They should understand the limitations of Rutherford’s atomic model in accounting for the motion of electrons around the nucleus by the view of classical mechanics. With the discovery of photoelectric effect and Einstein’s explanation, the particle nature of light is evidenced. Students should understand the details of photoelectric effect and electron diffraction by experiments or computing animations. Bohr’s postulates on discrete energy level of an electron in an atom should be treated as a first step to reveal the quantum nature of matter. The line spectra observed from the monatomic gases are used as evidence for energy levels of electrons. They should also recognise how the concept of wave-particle duality of electrons and light can successfully explain the phenomena observed. After studying this topic, students should also develop understanding on the development of nanotechnology and its contribution to our daily life. They would appreciate and briefly understand the use of advanced tools, such as electron microscope and scanning tunnelling microscope to see and manipulate substances at nano-scale. Students are encouraged to carry out project-type investigations in nanotechnology. Through exploration on social issues, students would be aware of the ethical and potential concerns (e.g. health) on the use of nanotechnology. Students would also learn the working principle of nanotechnology, and appreciate the contributions of the advancement of technology, the influence on our daily life and its limitations. The possible learning contexts that students may experience are suggested below for reference: Performing experiments on Rutherford’s atomic model: Using α scattering analogue apparatus to studying Rutherford scattering by means of a gravitational analogue of inverse square law Performing experiments on photoelectric effect: Using photocell (magnesium ribbon) to find out the threshold frequency Using photocell to measure the stopping voltage of monochromatic light Using photocell to measure the energy of photoelectrons induced by different 58 SECOND DRAFT colour of light Investigating the relationships among light intensity and the energy of photoelectrons Inferring the relationships among threshold frequency, stopping voltage and the kinetic energy of electron Performing experiments on the observations of absorption and emission spectra Performing experiments to demonstrate different physical properties of nano materials Using computing animations to enhance the understanding of students in: Rutherford’s atomic model Bohr’s model emission spectrum http://einstein.byu.edu/~masong/HTMstuff/bohrEX.html absorption spectrum photoelectric effect X-rays diffraction Investigating the principles of nanoscience in commercial products by the use of various properties of nano materials, e.g. impermeability to gas, water-repellence and transparency Challenging students’ preconceived ideas on atomic model, the nature of electrons and light Enriching students’ knowledge with the episodes of scientists e.g. Phillipp Lenard, Max Planck, Albert Einstein, Ernest Rutherford, Niels Bohr and de Broglie, in particular their contribution to the development of atomic physics Reinforcing students’ awareness of the importance of co-operation among scientists in investigation and discovery of the nature. Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the usefulness of models and theories in physics as shown in the atomic model and appreciate the wonders of nature to appreciate that the advancement of important scientific theories, such as Rutherford’s atomic model and photoelectric effect, can ultimately make huge impact on technology and society to appreciate the contributions of Rutherford, Bohr, Planck and Einstein that revolutionised the scientific thinking of their time 59 SECOND DRAFT to be open-minded in evaluating potential applications of theory of fundamental particles and nanotechnology to appreciate the efforts made by scientists to discover the nature of light and the structure of an atom to recognise the falsifiable nature of science theory and the importance of evidence in supporting scientific findings to recognise the importance of life-long learning in our future rapidly changing knowledge-based society and commit to self-learning STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the applications of nano-sized wires and tubes in other disciplines, e.g. Electronics, Optics, Medicine, Computing and Building Engineering the influence of nanotechnology on our health and lives the concerns on potential risks in using nanotechnology on the environment the roles of nanotechnology on economic growth in the world the ethical and social implications caused by the use of nanotechnology in areas such as military, medicine, and personal security and safety 60 SECOND DRAFT Topic VIII Energy and Use of Energy (27 hours) Overview The ability of human beings to use various forms of energy is the greatest development in human history. Electrical energy turns cities on and modern transportation powered by energy also links peoples together. Modern society is geared to using electricity as one of the energy sources. There are many reasons why electricity is the most common energy source used at home and in office. This elective begins by reviewing domestic appliances for lighting, cooking and air conditioning. These appliances show how physics principles are used to make our home a better and comfort place to live in. Students investigate the relative amounts of energy transferred when these appliances are in operation. They also learn how to calculate the cost from power rating of the appliance. The idea of energy changes being associated with energy transfer is raised, and students identify the energy changes associated with a range of appliances. This leads into the introduction of the Energy Efficiency Labelling Scheme informing the public to choose energy efficient household appliances for energy saving. The considerations of building and transportation then provide situations for students to study the factors affecting the energy performance in real context. The building materials provide the starting point for the discussion of the thermal properties of different materials to transfer energy. This leads into consideration into a building design to minimise the energy use to provide an appropriate internal environment without sacrificing the quality of that environment. Through the use of electric motors as energy converters in vehicles, students study the efficiency of motor compared to the combustion engine, with an attempt to reduce air pollution. There are many energy sources used as fuel that can be converted into electricity. The current fuel mix for generating electricity in Hong Kong includes coal, oil, natural gas, nuclear and pump storage. Students compare the efficiencies of different fuels and different ways of using the same fuel. Through a consideration of the design features of a solar panel, students investigate the aspect of conduction, convection and radiation as means of transferring energy from the nature. Different sources of energies cause various environmental impacts on society. When fossil fuels burn, a large amount of pollutants are discharged into the air. The pollutants cause atmospheric pollution, deteriorate the air quality and contribute to the greenhouse effects which may warm and damage the earth. Whereas nuclear power is very efficient but the disposal of dangerous radioactive waste materials continues to be problem. The growing concern about environmental impacts of energies polluting the environment has made environmentally friendly and alternative 61 SECOND DRAFT energies worth considering. In this connection, the emphasis is on the energy conservation principle and applies such concept to encourage efficient energy usage. In this connection, effective and efficient use of energy in a way that maintains and improves the environmental quality is also introduced. Efficiency can be described simply using input-output model. For example, a solar cell can be understood generally as a device that has the solar radiation as input and some useful form of energy as output. Despite the fact that Hong Kong has no indigenous energy resource, solar cells and wind power are introduced as local contextual examples to illustrate the concept of renewable energy sources. This elective increases students’ understanding of the applications of physics, uses of different energy sources and the implication of energy efficiency for environmental impacts. Learning Outcomes Students should learn: a. Students should be able to: Electricity at home energy consuming appliances in the home recognise the main source for domestic energy consuming appliances is electricity identify the main electric appliances used at home and describe briefly the energy changes involved lighting identify different types of lighting used at home describe briefly how filament light bulbs, gas discharge lamps (e.g. white fluorescent lamp, induction lamp) and Light emitting diodes (LED) produce visible light when an electric current passes through them recognise energy is absorbed to excite electrons from lower energy state to higher energy states while photons are emitted when excited electrons return to lower energy state recognise the relationship between radiated power of a bulb’s filament with its absolute temperature by P = eσT 4 A explain briefly why gas discharge lamps and light emitting diodes are more cost-effective lighting options than filament light bulbs 62 SECOND DRAFT Students should learn: Students should be able to: cooking without fire realise "cooking" is the application of heat to food explain briefly the working principles of electric hotplates, induction cookers and microwave ovens to generate heat for cooking and contrast with the working principle of thermal cookers identify the power rating of a cooker from the cooker’s instruction book and calculate the cost of running the cooker interpret the meaning of energy-efficiency values quoted by various manufacturers discuss factors affecting the energy-efficiency values and account for their differences solve problems involving energy-efficiency values moving heat around recognise an air-conditioner as a type of heat pump which transfers heat against its natural direction of flow apply the First Law of Thermodynamics to solve problems explain why heaters are usually placed near the floor while air-conditioners are always near the ceiling Energy Labelling Scheme realise the purposes of Hong Kong Energy Efficiency Labelling Scheme (EELS) for energy saving by informing the public to choose energy efficient products able to interpret typical energy labels for household appliances and apply related data (e.g. annual energy consumption in kW h/yr) in the label to solve problems identify examples of energy saving devices (through automatic control in street lights, air-conditioners, refrigerators, water heaters and escalators) 63 SECOND DRAFT Students should learn: b. c. Students should be able to: Energy performance in building and transportation materials used to improve energy performance of buildings state the key factors (e.g. climate, site locations, building envelops and building systems) to improve energy performance of buildings recognise building envelops (e.g. walls, roofs, windows, and skylights) are the important factors affecting energy performance in building define U value of a surface (rate of energy transfer per unit surface area), and apply these values to solve problems describe the main features of solar film installed on window and explain its function electric motor car describe main components of electric vehicles and describe briefly each of its functions describe how hybrid vehicles can improve the performance of electric vehicles compare and contrast the efficiency of a typical electric vehicle and a typical petrol vehicle explain why it is more efficient to use public transport (e.g. KCR and MTR) than using private cars Renewable sources of energy use of energy in Hong Kong recognise that the sun is a primary source of energy distinguish the different forms of non-renewable and renewable energies and state some examples of alternate energy resources state the use of energy in Hong Kong analyse the consumption data of different energy fuel types and the specific purposes for which these fuels are 64 SECOND DRAFT Students should learn: Students should be able to: consumed to provide a better understanding of energy consumption patterns and usage in Hong Kong renewable energy sources describe briefly the characteristics of renewable and non-renewable energy sources, for example, solar, tidal, water, wind, fossil fuel, and nuclear energy describe the structure of a solar cell in terms of p-type and n-type semiconductors, and explain how solar cells generate electricity define solar constant and solve related problems solve problems and analyse information about wind 1 power using p = ρAv 3 2 describe the energy conversion in a hydroelectric power station and solve problems using E = mgh non-renewable energy sources identify major characteristics of renewable energies describe energy conversions in a non-renewable energy power station (e.g. coal-fired plant, nuclear reactor, etc) and explain the importance of maximising the efficiency of energy conversions identify the pollution problems arising from the use of non-renewable energy sources environmental impact of energy consumption state the environmental impact of extraction, conversion, distribution and use of energy on the environment and society identify the different kinds of energy sources available to society and assess their suitability for particular situations state the interaction of energy with greenhouse gases: energy absorption and re-emission by greenhouse gases in relation to global warming 65 SECOND DRAFT Suggested Learning and Teaching Activities This topic should provide learning experiences for students to understand the production, conversion, transmission and utilisation of energy. The learning experience design should integrate the content domain, skills and process domain, values and attitudes domain of the physics curriculum in a meaningful pedagogy. These experiences should enrich teachers’ knowledge and stimulate their insight in using a contextual approach to empower students’ capability to acquire and construct these key concepts through context-based teaching. Students all have experience in their daily lives from which they construct knowledge. Thus daily life contexts and technological issue are presented to students. For examples, the Building Integrated Photovoltaic Design for Hong Kong, the Wind Turbine Project in Lamma Island, and the Ducted Wind Turbine Project can be used to arouse environmental and sustainable awareness of renewable energy sources amongst students. Discussion questions and learning activities relating to different available energy efficient technologies are used to motivate students to explore these contexts, hence discover and learn by themselves the underlying energy efficiency principles. Those knowledge, values and attitudes of being a smart energy consumer should also be infused in this topic. Generic skills used for communication, critical thinking, creativity and problem solving should be embedded in discussion leading to issues related to energy utilisation and conservation. Information, real data, themes, events and issues in Hong Kong that are illustrative to those key concepts should be provided to facilitate the learning and teaching. Students are firstly engaged by an event or a question related to the concept. Then the students participate in one or more activities to explore the concept. This exploration provides students with a common set of experiences from which they can initiate the development of their understanding. On need basis, the teacher clarifies the concept and defines relevant vocabulary. Then the students elaborate and build on their understanding of the concept by applying it to new situations. Finally, the students complete activities that will help them and the teacher evaluates their understanding of the concept. The possible learning contexts that students may experience are suggested below for reference: Performing an investigation to model the generation of an electric current by moving a magnet in a coil or a coil near a magnet Using the motor-generator kit to show students how electricity can be generated using mechanical energy Asking students to identify and analyse different energy sources, discuss the advantages 66 SECOND DRAFT and disadvantages of each energy source, and come to group agreement Analysing secondary information about the greenhouse gases effect on global warming Gathering and analysing information to identify how transmission lines are insulated from supporting structure, protected from lightning strikes and cleaned from dirt Performing an investigation to model the structure of a transformer to demonstrate how secondary voltage is produced and investigate the transformer action Gathering, processing and analysing information to identify some of the energy transfers and transformations involving the conversion of electrical energy into more useful forms in the home and industry Organising a class competition on solar cooking, wind power generator, or solar car race Investigating variables in the use of the sun for water heating, for cooking and for generating electricity Building a circuit to generate electricity from the sun Designing an investigation to determine whether heat or light generates electricity in a solar cell Visiting local power plants and the nuclear power plant in Daya Bay Inviting speakers from Electrical and Mechanical Services Department, Green Power, electric companies, Towngas, MTR, KCR or Environmental Protection Department to introduce up-to-date information on energy generation, transmission and consumption in society and alternative energy sources Gathering and analysing secondary information on different forms of non-renewable and renewable energies and state some examples of different energy resources. For example, solar, tidal, water, wind, fossil, and nuclear energy Studying environmental impact of extraction, conversion, distribution and use of energy on the environment and society, and the suitability for particular situations Being aware of a fossil fuel energy resource and a non-fossil energy resource with regard to accessibility, energy conversions required and efficiency of energy conversions Gathering and analysing secondary information on the interaction of energy with greenhouse gases: energy absorption, re-emission, radiation and dissipation by greenhouse gases Asking students what can be done to make the generation and use of electricity in Hong Kong more sustainable Asking students to measure the heat produced by a flashlight bulb and calculate the efficiency of the bulb Suggesting ways to control the transfer of solar energy into buildings Planning investigations to compare solar energy transfer through two different kinds of plastic film on windows Demonstrating an understanding of the applications of energy and its transfer and 67 SECOND DRAFT transformation Discussing energy usage at home and in office to infuse students more conscious of energy economy Asking students do an energy audit on his/her own home or school – for example, measure the amount of electrical energy used in a home in a month by reading the electric bill and estimate what proportion of this energy is used for lighting, for air-conditioning (or space heating), for heating water, for washing and cleaning, and finally for cooking Studying the Energy Efficiency Labelling Scheme in Hong Kong and information contained in Energy Labels Encouraging students to write about the proper use of domestic electrical appliances to reduce the cost of electricity and contribute to the worthwhile cause of saving energy Encouraging students to write about home safety in relation to the use of electrical appliances Discussing “ Life without electricity for a day” Discussing how the availability of electrical appliances has changed the life in Hong Kong over years Discussing family preparedness for periods of electrical outages Discussing the irreversibility of everything tends to become less organised and less orderly over time. Thus, in all energy transfers, the overall effect is that the energy is spread out uniformly. Examples are the transfer of energy from hotter to cooler objects by conduction, radiation, or convection and the warming of our surroundings when we burn fuels. Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the finite energy resources available to human and the need to save electrical energy for the reason of sustainable economy and environmental protection to be aware of the environmental implications on the use of different energy resources and to share the responsibility for a sustainable development of Hong Kong society to appreciate the efforts made by scientists to find more alternative environmental friendly energy resources to appreciate the efforts of mankind in the quest for the protection of the environment to be open-minded in evaluating potential applications of new technologies for improving 68 SECOND DRAFT energy efficiency to appreciate energy saving behaviour in daily life and to be committed to the good practices for energy consumption in daily life to be aware of the impacts of electricity on Hong Kong over years to be aware of the consumers’ responsibility to know the energy efficiency of home appliances via the energy efficiency labelling scheme to be aware of the importance of safety issues of electrical appliances and committed to safe usage to appreciate that the advancement of important scientific theories (such as semi-conductor theory and mass-energy conversion theory) can ultimately make huge impact on technology and society to be aware of the importance of life-long learning in our rapidly changing knowledge-based society and committed to self-learning STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the trade-off between the applications of different energy resources and the environmental impacts the safety problems associated with the storage and transportation of fuels pollutants and energy consumption by motor vehicles by restricting the use of private motor cars in order to reduce air pollutants the issue of detrimental effects of electromagnetic field emitted by high tension cable and power pylon the environmental implications and recent developments of the electric car as an alternative to the traditional fuel car and the role of the government on such issues the environmental impacts of the wind turbine on the scenic natural surroundings selection of sites for power plants is a matter for debate because such sites may alter coastal habitats 69 SECOND DRAFT Topic IX Medical Physics (27 hours) Overview This elective is concerned with the basic physics principles underlying vision and hearing of human to make sense of environment. It begins by considering the structures of eye and its optical system to adjust for different object distance. The concepts of defects of vision and the study of their corrections are introduced. The resolution is introduced to explain the fineness of detail discernible by the eye. The question of how colour vision is generated leads to the study of the rods and cones in the retina. Rods are responsible for the vision in dim light while cones are responsible for the more acute vision experienced in ordinary daylight conditions. A brief look at the structure of the ear serves to introduce students to concepts of transferring energy using a transducer and how different frequencies of sound waves are discriminated in the inner ear. Attention then turns to the applications of sound waves and visible light for seeing inside the body. A brief look at the working principles of ultrasound scanners and endoscopes serves to introduce students to pulse-echo, Doppler effect, and total internal reflection of waves. Ionising radiation, such as X-rays and gamma radiation, are introduced to students as an alternative means to give anatomical structures and functions of a body for medial diagnosis. In hospitals and clinics around the world literally hundreds of thousands of patients daily receive medical imaging tests in which X-rays, radionuclides, ultrasound beams and computed tomographic (CT) scanners are used. In virtually all of these devices physics has developed from our understanding of the electromagnetic spectrum, radioactivity of specific nuclides and wave properties of ultrasound beam. Such devices have enabled radiologists to see through the body without surgery. The medical uses of radioactive substances are introduced to students and the ways in which gamma radiation can be detected by gamma cameras to produce image for medical diagnosis are being considered. It should be emphasized that the development of new imaging modality is an evolutionary process. It may start with the discovery of a new physical phenomenon or a variation of the existing one. At all stages expertise in physics is essential. There is lots of interest in medical physics in the field of radiation oncology, nuclear medicine and radiology, and there are always students who want to know more. 70 SECOND DRAFT Learning Outcomes Students should learn: a. Students should be able to: Making sense of the eye and the ear the physics of vision recognise the basic structures of the eye and outline their respective functions realise that retina contains rods and three types of cones and appreciate the role of the cones in photo-detection, sensitivity and spectral response define resolving power and solve problems explain how the eye forms a focus image of an object and how the eye adjust for different object distances defects of vision and their correction understand the terms near point, far point, depth of field and accommodation distinguish between short sight (myopia), long sight (hypermetropia), presbyopia and astigmatism and describe how these defects can be corrected with suitable spectacle lenses recognise a simple structure of ear and describe qualitatively how the ear acts as a transducer in response to incoming sound waves realise human perception of relative intensity levels and the need for a logarithmic scale to reflect this define intensity level in decibel (dB) in terms of intensity I and threshold intensity Io, and use the decibel scale to solve problems sketch and interpret graphical representations of the variation of intensity levels (and curves of equal loudness) with frequency in logarithmic scale state the effects of excessive noises on hearing the physics of hearing 71 SECOND DRAFT Students should learn: b. Students should be able to: Sound and optical imaging physics of ultrasound identify the differences between ultrasound and sound in normal hearing range, and describe the wave properties of ultrasound at tissue boundaries recognise piezoelectric effect related to the generation and detection of ultrasound pulse define acoustic impedance Z = ρc and identify acoustic impedance of a variety of materials define the ratio of reflected to incident intensity as I r [Z 2 − Z1 ]2 = I o [Z 2 + Z1 ]2 recognise that the greater the difference in acoustic impedance between two materials, the greater is the reflected proportion of the intensity pulse using ultrasound to detect structures inside the body describe the principle of pulse-echo reflection of ultrasound describe how acoustic impedance, reflection, refraction and attenuation are applied to ultrasound describe factors affecting the quality of ultrasound image describe briefly about A-scans and 2 dimensional B-scans, and compare their differences describe the situations when different types of ultrasound scans would be used applications of ultrasound scans describe briefly the applications of ultrasound in obstetrics describe Doppler effect of a sound wave and explain briefly the use of Doppler ultrasonic to measure blood flow in blood vessels 2 fv define Doppler shift ∆f = and solve problems c 72 SECOND DRAFT Students should learn: fibre-optic endoscopes in medical diagnosis c. Students should be able to: recognise properties of optical fibres describe the physical principles of the optical system of an endoscope in relation to the total internal reflection, and the use of coherent and non-coherent fibre bundles explain qualitatively how an endoscope is used for internal imaging and the related advantages Medical imaging X-rays and radiographic imaging describe in simple terms the nature of X-rays explain briefly the physical principles of the production of X-rays using rotating-anode X-ray tube and methods of controlling the beam intensity and the photon energy explain in simple terms how the intensity I of a collimated X-ray beam varies with thickness x of a medium using the expression I = I o e − µx use of X-ray opaque material as illustrated by the barium meal technique for radiographic image detection describe in simple terms the limitation of the radiographic imaging CAT scans in medical diagnosis describe in simple terms the use of a rotating beam in the X-ray computed tomography (CT) scanner describe in simple term the CT scanner and understand quantitatively the principle of computerised axial tomography (CAT) recognise CAT showing X-rays attenuation through a cross-section of the body compare CAT scans as a diagnostic tool with conventional X-rays and ultrasound radioactivity and the use of radioisotopes in medical diagnosis understand the nature of radioactivity and give a simple description of decay curves describe the principles of the use of radioisotopes to study 73 SECOND DRAFT Students should learn: Students should be able to: the functional information about parts of the body or particular organs identify the characteristics of radioisotopes using to study the body’s function for medical uses describe the use of a Gamma camera to obtain diagnostic information from radioisotopes state radioactive isotopes used in Single Photon Emission Tomography (SPET) compare radionuclide image of a bone scan with a conventional X-ray film image understand qualitatively the principle of SPET understand the structure of film badges and its function for personnel monitoring of ionising radiation recognise the health risk and safety precautions for ionisation radiation Suggested Learning and Teaching Activities The main focus in this topic is on the physics and its applications in medicine using non-ionizing radiation as well as ionization radiation for medical diagnosis. The eye is used to model an optical device while the ear as a mechanical transducer that enables human to react to change in the environment through the nervous reactions. Historical perspectives of the discoveries of X-rays and radioactivity can be introduced. For example, perhaps the earliest medical imaging experiment was the imaging by Rontgen of his wife’s hand within weeks after he discovered X-rays. Ultrasound as medical imaging modality is really an application of Sound Navigation and Ranging developed during the Second World War. Ultrasound scanners were used to enable the foetus to be viewed during pregnancy. The use of ionization radiation in medicine may be said to stem from two discoveries at the end of the 19th century. In 1895 Roentgen discovered X-rays and in 1896 Becquerel discovered radioactivity. Subsequently, both of these discoveries resulted major impact in how medicine is practiced. X-rays have since been used to produce images of the inside body and in the treatment of cancer, with radionuclides also being used for both purposes. The use of X-rays to investigate the body results in the development of the field of diagnostic radiology. The use of X-rays along with the treatment with the radiation emitted by radioactive decay 74 SECOND DRAFT for the treatment of malignant tumours resulted in the development of the field of radiation oncology or radiotherapy. After the Second World War numerous artificially produced radionulides became available. As well as being used for the treatment of cancer, radionuclides were used to localise specific organs and diseases in the body. This resulted in the development of the field of nuclear medicine. With the results of the development of digital computers it was subsequently possible to reconstruct cross-sectional images of the body, resulted in the 1970s in computerized tomography. Such technological advancement helps students to appreciate the importance of physics, mathematics, engineering, and computer science in the design of imaging devices. Students should develop skills in searching information from World Wide Web. Lots of up-to-date information and image data for educational purposes are available on the Web. For example, one way to start with would be to ask the class to explore the difference of image obtained from various scans, such as ultrasound, SPET and CAT, in relation to the information content from the images. Furthermore, the concepts of representing image in number can be introduced, and so manipulating those numbers which can modify the image. The combination of visualisation and numerical process produce enormous impact for extracting and representing image data. Resolution is a fundamental characteristic of all measuring systems. The resolution of any instrument is the smallest difference which is detectable. In this connection, students are encouraged to carry out comparison to differentiate the appearance of specific images and examine the smallest size of things which can be distinguished so as to introduce the concepts relating to image resolution. It is also interesting to note that the idea of resolution also applies to the grey levels in the digital images. A simplified version of back projection algorithm can be used to simulate image reconstruction from projection data. To arouse the interest of students, class may be asked to discuss open questions. For examples: Is ultrasound scan safe in pregnancy? How do you detect cancer? Are computers making doctors less important? Students are also encouraged to extend their reading from textbooks to articles, popular science magazines and the Web. In particular, there is relevant collection of articles in the e-museum at Nobel Foundation for students’ browsing. If students follow their own reading interests, chances are good that they will find many pages there that convey the joy these Laureates of Nobel Prize have in their work and the excitement of their ideas. The possible learning contexts that students may experience are suggested below for reference: Observing images produced by ultrasound scans, endoscopes, X-ray film, CAT scans 75 SECOND DRAFT and SPET Demonstrating the principles of pulse-echo using ultrasound transmitters and receivers Solving problems and analyse information to calculate the acoustic impedance of a range materials, including bone, muscle, soft tissue, fat, blood and air and explaining the types of tissues that ultrasound can be examined Using a pair of ultrasound transmitter and receiver to investigate the amplitude of echo from reflectors of different materials Observing an ultrasound image of body organs and gather information Estimating the resolution of an ultrasound image of a baby if the image size is about 250 mm across and high by a square array of 256×256 Observing the flow of blood through the heart from a Doppler ultrasound video image Identifying data sources and gathering information to describe how ultrasound is used to measure bone density Solving problem and analysing information using acoustic impedance and intensity ratio of reflected and incident signals Discussing and observing two X-ray images with and without showing fracture of bone Discussing – “As late as in the 1950s X-rays were used to ensure well fitting shoes. Why is it no longer used today?” Gathering information about deaths due to tuberculosis in 1940s and suggesting a method to diagnose the disease so as to reduce its risk Using a dental film and a gamma source to demonstrate film exposure of X-rays and absorption of X-rays Observing a CAT scan image and comparing the information provided by CAT scans to that provided by an conventional X-ray image for the same body part Performing a first-hand investigation to demonstrate the transfer of light by optical fibres Gathering secondary information to observe internal organs from images produced by an endoscope Using dice to simulate radioactive decay and study the random nature of decay in radioactive nuclides Comparing an image of bone scan with an X-ray image Comparing a scanned image of one healthy body part or organ with a scanned image of its diseased counterpart Comparing the advantages and disadvantages of traditional X-ray images, CAT scans and SPET scans Gathering, analysing information and using available evidence to assess the impact of medical applications of physics on society Discussing the issues related to radiation safety using non-ionization radiation and 76 SECOND DRAFT ionization radiation for imaging Reading articles from e-museum (http://nobelprize.org/physics/) to trace historic development of CT, explore what physicists do and their impact of scientific thought on the society Values and Attitudes Students should develop intrinsically worthwhile values and attitudes in studying this topic. Some particular examples are: to be aware of the importance of safety measures in relation to ionisation and non-ionisation radiation to be aware of the potential danger from X-rays and radiation from radioactive sources to pregnant woman to adopt a cautious attitude in matters concerning public safety to be aware of the implications on the use of different modes of imaging technology and to make an effort in reducing radiation exposure in daily life to appreciate some of the factors which contribute to good health, and the importance of personal responsibility in maintaining it to appreciate the role of the medical and associated services provided in Hong Kong and the role of various people within them to appreciate the relative importance of preventative and curative services to be open-minded in evaluating potential applications of principles in physics to new medical technology to appreciate the efforts made by scientists to find more alternative methods of medical diagnosis to appreciate that the advancement of important scientific discoveries (such as radioactivity and X-rays) can ultimately make huge impact on society to appreciate the contributions of physics, mathematics, engineering and computer science that revolutionised the technology advancement in medical imaging to recognise the roles of science and technology in the exploration of medical science and to appreciate the efforts of mankind in the quest for the understanding of human body to recognise the importance of life-long learning and self-learning in knowledge-based society 77 SECOND DRAFT STSE connections Students are encouraged to develop an awareness of and comprehend issues associated with the interconnections of science, technology, society and the environment. Examples of issues and contexts related to this are: the issue of the effects of radioactive waste from medical applications on the environment the issue of who decides how much money is spent on medical research How often should be screened via X-rays against possible case of tuberculosis (TB)? How dangerous or risky is when patients are imaging using conventional X-rays, CAT, ultrasound and SPET How can abnormality in the foetus be detected? the issue of using CT scanners in archaeology investigations medical diagnosis: the dilemma in choosing between various devices for optimum medical diagnosis to accept uncertainty in the descriptions and explanations by medical diagnosis, and the issue of false positive and false negative the ethical issue of a doctor to decide whether or not to turn off a life-supporting machine 78 SECOND DRAFT Investigative Study (16 hours) Topic X Investigative Study in Physics (16 hours) Overview This study aims to provide opportunity for students to design and conduct an investigation with a view to solving an authentic problem. Investigative studies are inquiry-oriented activities to provide students with direct exposure to experiences that reinforce the inquiry nature of science. In the task, students have to analyse a problem, plan and conduct investigation, gather data, organise their results, and communicate their findings. In this connection, students are involved actively in their learning, formulate questions, investigate widely and then build new meanings and knowledge. A portion of the curriculum time is set aside for this purpose. Students are expected to make use of their knowledge and understanding of physics, together with generic skills (including but not limited to creativity, critical thinking, communication and problem-solving) to engage in group-based investigative study. Through the learning process in this study, students can enhance their skills both with practical and non-practical nature, and develop awareness of working safely of investigation. Learning outcomes The following outcomes are expected: Students should be able to justify the appropriateness of an investigation plan put forward suggestions on ways to improve validity and reliability of a scientific investigation use accurate terminology and appropriate reporting styles to communicate findings and conclusions of a scientific investigation evaluate the validity of conclusions with reference to the process of investigation and the gathered data and information demonstrate mastery in manipulative skills, skills in observation and also good attitudes in general show appropriate awareness of importance of working safely in laboratory elsewhere 79 SECOND DRAFT Implementation Prerequisite - Students should have some experiences with and provided with guidelines on the following aspects before conducting an investigative study: Selecting an appropriate question for the task Searching for relevant information from various sources Writing an investigation plan Writing up a laboratory report or making a poster for presentation Grouping - The investigation can be conducted in groups of 4 or 5 students. Timing - The investigation can be undertaken on completion of a task requiring students to plan an experiment for an investigative study, indicating the variables to be measured, the measurement they will make, and how they will record and present the data collected. For instance, an investigative study on the topic “projectile motion” can be carried out towards the end of the senior secondary two (SS2) and completed at the start of the senior secondary 3 (SS3). In other words, students can develop their investigation plan from March to May of SS2, the investigation can be conducted at the end of SS2, and the presentation to be done at the start of SS3. Alternatively, it is also possible to conduct an investigation in conjunction with the learning of the topic. With reference to the above example, it is possible to conduct investigation in SS2 and complete in SS3. Time is allocated for the following activities: Searching and defining questions for investigations Developing an investigation plan Conducting the investigation Organizing, documentation and analysing data for a justified conclusion Presentation of findings and written reports / making posters Suggestions - The topics selected should lend itself to practical work. The study should focus on authentic problems, events or issues which involve key elements like “finding out” and “gathering first-hand information”. In addition, to maximise the benefit of learning from the investigation within the time allocated, teachers and students should work together closely to discuss and decide on an appropriate and feasible topic. 80 SECOND DRAFT Some possible topics for investigative study are suggested below: Build a box which has the best effect of keeping the temperature of an object or has the best cooling effect Measure the distance between two very far away points, e.g. the distance between the earth and the moon Measure the height and the size of a building Principle and applications of a solar cell Construction and testing of a home-made wind turbine Measure the speed of a water rocket Studying articles about the latest astronomy discoveries can promote students’ interest in modern science and strengthen their self-learning ability. Oral or written presentation in class is encouraged Investigating the principles of nanoscience in commercial products by the use of various properties of nano materials, e.g. impermeability to gas, water-repellence and transparency Reading articles from e-museum (http://nobelprize.org/physics/) to trace historic development of CT, particularly memorable description of what physicist do and their impact of scientific thought on the society Assessment To facilitate learning, teachers and students can discuss and agree on the following assessment criteria with due consideration of factors that may facilitate or hinder the implementation of the study in a particular school environment. Feasibility of the investigation plan (the study is a researchable one) Understanding of relevant physics concepts, concerns on safety Manipulative skills and general attitudes Proper data collection procedure and ways to handle possible sources of error Ability to analyse and interpret data obtained from first-hand investigation Ability to evaluate validity and reliability of the investigation process and the findings Ability to communicate and defend the findings to the teacher and peers Appropriateness in using references to back up the methods and findings Attitudes towards the investigation 81 SECOND DRAFT A number of assessment methods like observation, questioning, oral presentation, poster presentation session and scrutiny of written products (investigation plan, reports, posters, etc.) can be used where appropriate. 82 SECOND DRAFT Chapter 3 Curriculum Planning 3.1 As a senior secondary science subject in the Key Learning Area of Science Education, physics builds on the junior secondary science curriculum. Students’ science learning experiences in junior secondary science lay the foundation for learning senior secondary physics. In this connection, this chapter describes the linkages of knowledge, concepts, process skills and generic skills between the two levels of study. Teachers may consider the information described in this chapter as a reference for planning their school-based senior secondary physics curriculum for their students. 3.2 It is a well known fact that students have individual differences in interests, strength and aspirations. Students have different learning styles – visual, auditory, and kinesthetic & tactile, as well as different alternative science concepts. It is desirable to organise this curriculum in a way that addresses the individual needs of students. Some teachers may prefer certain learning and teaching approaches over the others, and they believe these approaches help elevate the effectiveness, efficiency and quality of students’ learning. Thus, teachers are encouraged to organise the curriculum in meaningful and appropriate ways to ensure “fit for the purpose”. This chapter attempts to describe some ideas for teachers to deliberate on when they need to design their own school-based curriculum for senior secondary physics. Interfacing Junior Secondary Science Curriculum 3.3 This curriculum builds on the CDC Syllabus for the Secondary Science (S1-3) published in 1998. The Junior Science Curriculum starts with the topic “Energy” which helps students appreciate energy as one of the fundamentals of physics, learn some basic knowledge of physics, acquire some basic practical skills and develop positive attitudes towards physics. Furthermore, through the study of this curriculum, students can consolidate their knowledge and understanding in physics as well as the scientific skills acquired in their junior science course. 3.4 Students should have developed some basic foundation and understanding in physics through their three-year junior secondary science course. The learning experiences acquired provide a concrete foundation and serve as a ‘stepping stone” for senior secondary physics. The following table shows how respective physics topics in the CDC Syllabus for Science (S1-3) are related to different topics in this curriculum. 83 SECOND DRAFT Science (S1-3) Unit Title 1.4 Conducting a simple scientific investigation 4.1 Forms of energy 4.2 Energy changes 4.4 Generating electricity 4.5 Energy sources and we 6.1 States of matter 6.2 Illustrations for the support of the claims of the particle theory 6.3 Particle model for the three states of matter 6.4 Gas pressure 8 Physics (Senior Secondary) Topic X VIII Title Investigative Study Energy and Use of Energy and other parts in the curriculum I Heat Transfer and Gases Making Use of Electricity IV Electricity and Magnetism 9.1 Forces II Force and Motion 9.2 Friction 9.3 Force of gravity 9.4 A space journey I Heat Transfer and Gases 9.5 Life of an astronaut in space II Force and Motion 9.6 Space exploration VI Astronomy and Space Science 11.2 How we see III Wave Motion 11.3 Limitations of our eyes IX Medical Physics 11.4 Defects of the eye 11.5 How we hear 11.6 Limitations of our ears 11.7 Effects of noise pollution 15 Light, Colour and Beyond III Wave Motion 84 SECOND DRAFT Progression of Studies 3.5 To help students with different aptitudes and abilities explore their interests in different senior secondary subjects, the report New Academic Structure for Senior Secondary Education and Higher Education – Action Plan for Investing in the Future of Hong Kong (Education and Manpower Bureau, 2005) recommends the idea “progression of studies”. Chinese Language, SS3 English Language, Mathematics, X1 X2 (X3) X1 X2 (X3) Liberal Studies Chinese Language, SS2 English Language, Mathematics, Liberal Studies Chinese Language, SS1 English Language, Mathematics, X1 X2 (X3) (X4) Liberal Studies Core Subjects Elective Subjects Other Learning Experiences ( ) optional In short, schools may choose to offer a total of 4 elective subjects at SS1 level, 3 at SS2 level and 3 at SS3 level respectively for their students. 3.6 With the suggestion mentioned above, a number of topics have been identified from this curriculum for students intended to explore their interests in science subjects. The topics identified should help to lay the foundation for learning physics and facilitates students to become life-long learners in science and technology. Possible arrangement of the topics suggested is described in the scheme below. Schools can deliberate on this scheme whether it can facilitate the progression of study in senior secondary physics. 85 SECOND DRAFT Topic I Remarks Heat Transfer and Gases a. Temperature, heat and internal energy b. Transfer process c. Change of state Include all the subtopics except subtopic (d) which can be studied in a later stage d. Gases II Force and Motion Include subtopic (a), (b) and (d) only a. Position and movement b. Force and motion c. Motion in two dimensions d. Work, energy and power e. Momentum f. Gravitation 3.7 III Wave Motion a. Nature and properties of waves b. Light c. Sound X Investigative Study in Physics include only subtopic (b) It can be studied together with basic scientific skills and practical skills but not for assessment. Considering the rapid advancement in the world of science and technology, many contemporary issues and scientific problems have to be tackled by applying science concepts and skills acquired in wider contexts. Thereby, it is more beneficial for students to gain a broad learning experience in the three disciplines. To cater for students who are more interested in learning science and those intended taking two science subjects in science education, schools are suggested to offer a broad and balanced science curriculum for students in SS1, including all the three selected parts from biology, chemistry and physics. 86 SECOND DRAFT 3.8 During SS1, students may explore their interests in science through studying the three parts and have more understanding of the different nature and requirements of the respective disciplines. They will be more able to identify their interests and strengths for choosing their specialized study in higher forms. Moreover, the broad and balanced foundation laid in the first year of study will benefit them from associating the related concepts and skills acquired in various disciplines of science for their specialised study and keeping abreast of their interests of science in wider contexts. The diagram below is an example on how schools can organise a progression of study for students who wish to have more science learning. SS3 SS2 SS1 Physics Science(Bio, Chem) or Biology or Chemistry (Other Subject) Physics Science(Bio, Chem) or Biology or Chemistry (Other Subject) Physics Biology Chemistry (Other Subject) ( ) optional 3.9 Under the New Senior Secondary Academic Structure, there will be flexibility to allow students to take up the study of Physics at SS2. For these students, similar sequence of learning still applies. Schools may consider allocating more learning time and providing other supporting measures (e.g. bridging programmes) to these students so that they can catch up the foundation knowledge and skills as soon as possible. 87 SECOND DRAFT Suggested Learning and Teaching Sequences 3.10 This chapter illustrates how teachers may approach the design of teaching and learning activities, the development of curriculum planning which reflect the ethos of the teachers and the kinds of learning outcomes, and the development of personnel and resources. The essence of physics lies in the creation of concepts, models and theories which must be matched with experience and have internal consistence. It is worthwhile to note that concepts or principles are a special form of knowledge in enhancing students’ understanding of physics. Teachers need to understand students’ learning difficulties and misconceptions and adopting constructivist approaches to teaching physics. Making use of contextual examples and their relation with key concepts enables a meaningful learning in students. Students hold a number of intuitive ideas about the physical world based on their everyday experience. Developing concepts within a context that is familiar to students provides an opportunity for students to become more aware of their intuitive ideas. Alternatively, by connecting key concepts with the historic process through which physics was developed, teachers are in a better position to anticipate and understand students’ intuitive ideas, which often align with historical controversies. Some of the suggested topics should permeate the whole curriculum so that students come to appreciate inter-connections between different topics. The sequence is organised in a way that learning starts with some topics using more concrete content and less difficult concepts, and then progress onto some topics that are more abstract and subtle. As an example, students need to understand the concepts of momentum before they can appreciate the kinetic model of gases. 3.11 Topics like “Temperature, heat and internal energy”, “Transfer processes”, “Change of state”, “Position and movement”, “Force and motion”, “Work, energy and power”, “Nature and properties of waves” and “Light” provide a vast amount of concrete relevant contextual examples, which facilitate students in constructing concepts at SS1 level. These examples provide opportunities to connect concepts and theories discussed in the classroom and in textbooks with observations of phenomena. Teachers may engage students with conceptual organisers such as concepts map to foster the learning of physics. Students often find Newton’s laws of motion counter-intuitive, and studying 2-dimensional projectile motion adds further complication. To ensure meaningful learning, teachers need to check the essential prerequisite knowledge and structured the problem in small manageable steps which take the form of a simple sequencing task: a set of words and phrases (displacement; velocity; acceleration; change in direction; change in velocity; curved path; unbalanced force) to connect by drawing arrows to build up a chain of logical connections. Students can review their previous learning and prior knowledge at different stage of learning. For example, teachers introduce preliminary basic concepts of force and motion in SS1, and refine these 88 SECOND DRAFT concepts in SS2. The physics curriculum provides flexible framework within which schools will design learning sequences suited to the needs of their students, and other factors appropriate to the teachers. Teachers can deliberate on whether or not to adopt the sequence as suggested. Furthermore, teachers are reminded that they could exercise their professional judgments to design the most appropriate teaching and learning sequence to be used. It is likely that different sequences help be adopted in different schools to benefit different ability groups of students. Through the study of the various topics in the compulsory and elective parts, students should develop progressing sophisticated concepts in physics. The following teaching sequences are therefore given as suggestions only. Topics Level I Heat transfer and gases (except gases) II Force and motion (except 2D motion, momentum and gravity) III Wave motion (light only) X Investigative study in Physics II Force and motion (2D motion, momentum and gravity) I Heat transfer and gases (gases) III Wave motion (except light) IV Electricity and magnetism X Investigative study in Physics V Radioactivity and nuclear energy VI Astronomy and space science* VII Atomic World* Medical physics* X Investigative study in Physics SS2 SS3 VIII Energy and use of energy* IX SS1 * denotes a topic in the elective part (2 out of 4) Curriculum organisation One aspect in teaching topics, especially at SS1 level, is finding the most appropriate level of simplification of the subject matter. For example, when students are studying the concept of “heat” in physics, some key ideas are essential and should be introduced at SS1 level while some complicated topics should be deferred until later. It should 89 SECOND DRAFT have a balance between the breadth and the depth of the curriculum so that students can follow. From this perspective, teachers should judge the appropriate level of simplification, the order in which to present ideas, and the pace at which to deliver the key ideas in order to help students construct as scientifically valid a model of a topic as possible. Figure below shows one possible simplification to relate heat, temperature and internal energy. In this case, heat flows due to a temperature difference and this can lead to a change in temperature, or a change of state. This is explained in terms of a molecular model, where the heat flow increases the internal energy of the particles. The internal energy of the particles can be kinetic and potential, and the temperature is a measure of the average kinetic energy of the particles. The scheme may be considered as a concept map, with each arrow representing a relationship between the concepts in the boxes connected. It is worth to note that students may need prior knowledge, such as of kinetic energy and potential energy, in the topic “Force and motion” to understand the concepts of internal energy of the particles. Thus this part of thermal physics may run concurrently with “Force and motion”. temperature difference heat state temperature internal energy latent heat kinetic energy potential energy Integration of major topics The curriculum puts forward the ideas of compulsory and elective parts. The compulsory part provides fundamental concepts of physics in SS1 and SS2, followed by a range of topics in the elective part from which students must choose any two. The topics in the elective part can be used as vehicles for teaching the special interests of students. This provides excellent opportunities to introduce and follow up the extension of the key concepts. For instance, knowledge and concepts, such as nature and properties of waves, light and sound in “Wave Motion” are further reinforced in 90 SECOND DRAFT “Medical Physics”, where sound and optical imaging, and medical imaging are used as extension tasks. The extension task is demanding and capable of stretching the abilities of the students. The purpose of this arrangement is to avoid loading students with a bunch of abstract concepts in a short period of time, in particular, at the early stage of senior secondary study. Furthermore, it also aims to provide opportunity for students to revisit their learning in previous year of study at SS2. Some teachers may prefer to introduce the concepts related to wave motion in one go. Other teachers may organise their own curriculum in a way that the topics “Wave Motion” and “Medical Physics” are run concurrently. Similar integration can be extended to topics like “Electricity and Magnetism” and “Energy and Use of Energy”, as well as “Force and Motion” and “Astronomy and Space Science”. Integration of the Investigative Study with major topics It has been recognised that inquiry activities have a central and distinctive role in physics education. The interaction among theories, experiments and practical applications is fundamental to the progress of physics. Teachers can encourage students to reconstruct their knowledge using inquiry activities within a community of learners in their classroom and on the basis of personal experiences. Meaningful learning can occur if students are given sufficient time and opportunities for interaction and reflection, the generic skills are further enhanced and extended. Investigative Study in Physics is a learning opportunity for student to apply their physics knowledge in scientific investigation to solve an authentic problem. The learning in different parts of the curriculum together with the experience in the Investigative Study should pave the way for students to become self-regulated and competent life-long learners. Teachers may encounter students, who are mathematical inclined, intend to carry simulations on data modelling. To cater the need of these students, teachers can organise the learning of the topics in the elective part (e.g. Astronomy and Space Science) in parallel with the Investigative Study. In simulation runs, the students explore the relationship between assumptions and predictions about the phenomenon. This helps students apply physics concepts to analyse and solve problems, and at the same time develops various scientific skills and processes. Teachers can also adopt an alternative learning and teaching strategy. For example, by solving the problems through gathering information, reading critically, learning new knowledge on their own, discussion, investigation etc, and students can master knowledge and understanding required in the Investigative Study for the topic “Energy and Use of Energy”. Similar integration can also be extended to other topics in the compulsory part and the elective part including “Atomic World” and “Medical Physics”. 91 SECOND DRAFT Chapter 4 Learning and Teaching 4.1 The curriculum has an in-built flexibility to cater for the interests, abilities and needs of students. This flexibility also provides a means to bring about a balance between the quality and quantity of learning. Teachers should provide ample opportunities for students to engage in a variety of learning experiences, such as investigations, discussions, demonstrations, practical work, field studies, model-making, case-studies, questioning, oral reports, assignments, debates, information search and role-play. Teachers should give consideration to the range of experiences that would be most appropriate to their students. The context for learning should be made relevant to daily life, so that students will experience physics as interesting and important to them. 4.2 Practical work and investigations are essential components of the curriculum. They enable students to gain personal experience of science through hands-on activities, and to develop the skills and thinking processes associated with the practice of science. Participation in these activities encourages students to bring scientific thinking to the processes of problem-solving, decision-making and evaluation of evidence. Engaging in scientific investigation enables students to gain an understanding of the nature of science and the limitations of scientific inquiry. Designing Learning Activities 4.3 Teachers should motivate students through a variety of ways such as letting them know the goals and expectations of learning, building on their successful experiences, meeting their interest and considering their emotional reactions. Learning activities should be designed according to these considerations. Some examples of these activities are given below. Article reading Students should be given opportunities to read independently science articles of appropriate breadth and depth. The abilities to read, interpret, analyse and communicate new scientific concepts and ideas can then be developed. Meaningful discussions on good science articles among students and with teachers may also be used to strengthen general communication skills. The abilities of self-learning developed this way will be invaluable in preparing students to become active life-long learners. 92 SECOND DRAFT A variety of articles, which may be used to emphasise the interconnections between science, technology and society, will serve the purposes of broadening and enriching the curriculum, bringing into which current developments and relevant issues. Teachers may select suitable articles for their own students according to their interest and abilities, and students are encouraged to search for such articles from newspapers, science magazines and the Internet. The main purpose of this part of the curriculum is to encourage reading. The factual knowledge acquired is of relatively minor importance; whereas rote memorization of the contents is undesirable and should be discouraged. Discussions and debates Discussions and debates in the classroom promote students' understanding, and help them develop higher order thinking skills as well as an active learning attitude. One of the most effective ways to motivate students is to make discussions or debates relevant to their everyday life. Presenting arguments allows students to extract useful information from a variety of sources, to organise and present ideas in a clear and logical form, and to make valid judgements based on scientific evidence. Teachers can start a discussion with issues related to science, technology and society, and invite students to freely express their opinions in the discussion, at the end of which students can present their ideas to the whole class and receive comments from their teacher and classmates. Teachers must avoid discouraging discussions in the classroom by insisting too much and too soon on an impersonal and formal scientific language. It is vital to accept relevant discussions in students’ own language during the early stages of concept learning, and to move towards precision and accuracy of scientific usage in a progressive manner. Practical work Physics is a practical subject and thus practical work is essential for students to gain a personal experience of science through doing and finding out. In the curriculum, designing and performing experiments are given due emphases. Teachers should avoid giving manuals or worksheets for experiments with ready-made data tables and detailed procedures, for this kind of instructional materials provide fewer opportunities for students to learn and appreciate the process of science. With an inquiry-based approach, students are required to design all or part of the experimental procedures, and to decide what data to record and how to analyse and interpret the data. Students will show more curiosity and sense of responsibility for their own experiments leading to significant gains in their basic scientific skills. 93 SECOND DRAFT Moreover, experiments are better designed to “find out” rather than to “verify”. Teachers should avoid giving away the answers before the practical work, and students should try to draw their own conclusions from the experimental results. The learning of scientific principles will then be consolidated. Experiments Include designing and planning prediction of results manipulation of apparatus collection of data consideration of safety Conclusions and interpretations Include analysis of experimental results evaluation of predictions explanation for deviations from predictions Scientific Principles Include generalisation of patterns and rules from conclusions and interpretations Project Learning Learning through project work, a powerful strategy to promote self-directed, self-regulated and self-reflecting learning, enables students to connect knowledge, skills, and values and attitudes, and to accumulate knowledge through a variety of learning experiences. It also serves to develop a variety of skills such as scientific problemsolving, critical thinking and communication. Project work can be carried out individually or in small groups, and students will plan, read and make decisions over a period of time. Project work carried out in small groups can enhance the development of collaboration skills, while that involving experimental investigations can help develop practical skills as well. Searching and presenting information Searching for information is an important skill to be developed in the information era. Students can gather information from various sources such as books, magazines, scientific publications, newspapers, CD-ROMs and the Internet. Searching for information can cater for knowledge acquisition and informed judgements by students, but the activity should not just be limited to the collecting of information. Its selecting and categorizing and the presentation of findings should also be included. 94 SECOND DRAFT Teaching with a Contextual Approach 4.4 Learning is most effective if it is built upon the existing background knowledge of students. Learning through a real-life context accessible to students will increase their interest and enhance the learning of physics. The context-based learning highlights the relevance of physics to students’ daily life and can be employed to enhance their awareness of the inter-relationships between science, technology and society. When the original concepts have been learned with effectiveness, confidence and interest, the transfer of concepts, knowledge and skills to other contexts can then be made. Teachers are strongly encouraged to adopt a contextual approach in an implementation of the curriculum. Using Information Technology (IT) for Interactive Learning 4.5 IT is a valuable tool for interactive learning, which complements the strategies of learning and teaching inside and outside the classroom. Teachers should select and use IT-based resources as appropriate to facilitate students’ learning. However, an improper use of IT might distract student attention, have little or no educational value and may sometimes cause annoyance. 4.6 There are numerous and growing opportunities to use IT in a science education. IT can help search, store, retrieve and present scientific information. Interactive computer-aided learning programmes can enhance the active participation of students in a learning process. A computer-based laboratory interface allows students to collect and analyse data, vary parameters, and find out mathematical relationships between variables. Simulation and modelling tools can be employed to effect exploratory and interactive learning processes. Providing Life-wide Learning Opportunities 4.7 A diversity of learning and teaching resources should be used appropriately to enhance the effectiveness of learning. Life-wide learning opportunities should be provided to widen the exposure of students to the scientific world. Examples of learning programmes serving this purpose include popular science lectures, debates and forums, field studies, museum visits, invention activities, science competitions, science projects and science exhibitions. Students with good abilities or a strong interest in science may need more challenging learning opportunities. These programmes can stretch students’ science capabilities and allow them to develop their full potential. 95 SECOND DRAFT Chapter 5 Assessment Aims of assessment 5.1 Assessment is an integral part of the learning and teaching cycle. It is the practice of collecting evidence of student learning. The aims of assessment are to improve learning and teaching as well as to recognise the achievement of students. Therefore, the design of assessment should be aligned with the learning targets, the curriculum design and the learning progression. At the same time, a diversity of assessment modes should be adopted to attain the goal of assessment for learning. Internal Assessment 5.2 Internal assessment refers to the assessment practices that schools will employ as part of the learning and teaching strategies during the three years of study in physics. These practices should be aligned with curriculum planning, teaching progression, student abilities and the local school contexts. Internal assessment includes both formative and summative assessment practices. The information collected will help to motivate and promote student learning. The information will also help teachers to find ways of promoting more effective learning and teaching. A range of assessment practices, such as written tests, oral questioning, observation, investigative studies, practical work and assignments, should be used to promote the attainment of various learning outcomes. Moreover, values and attitudes can be assessed in school and be reflected in the student report card of the “Student Learning Profile”. Public Assessment 5.3 Public assessment of the subject Physics refers to the assessment measures that lead to a qualification in the subject to be offered by the Hong Kong Examinations and Assessment Authority (HKEAA). It provides information about the standards and achievement of students based on the learning outcomes listed in this Curriculum and Assessment Guide. Public assessment of Physics will comprise two components: a Written Examination and School-based Assessment (SBA). The assessment tasks used in the public examination and the SBA will address the learning targets laid down in this curriculum, and be aligned with the curriculum emphases, such that the potential of assessment can be 96 SECOND DRAFT harnessed to encourage teaching and learning in the directions intended in this curriculum framework. Public Examination 5.4 The public examination will consist of two papers; one focuses on the Compulsory Part of the Curriculum and the other mainly on the Elective Part. Different types of items will be used to assess students’ performance in a broad range of skills and abilities. The types of items will include multiple choice questions, short questions and structured questions. These types of items are currently adopted in the HKCE and HKAL examinations. When the curriculum content and the learning outcomes are finalised, sample papers will be provided to schools to illustrate the format of the examination and the standards at which the questions are pitched. School-based assessment 5.5 SBA refers to the assessment administered in schools in which a student’s performance is assessed by the student’s own teacher. The merits of adopting SBA are as follows: (i) SBA helps improve the validity of public assessment, since it can cover a more extensive range of learning outcomes, through employing a wider range of assessment practices that cannot be implemented in public examinations. (ii) SBA allows for continuous assessment of the work of students. It provides a more comprehensive picture of student performance throughout the period of study rather than their performance in a one-off examination. Since assessments are typically based on multiple observations of student’s performance, SBA can improve the reliability of the overall assessment. 5.6 are: (i) Embodying the two merits above, the rationales of implementing SBA in Physics To assess students’ skills in the performance of practical work and their abilities in carrying out scientific investigations. 97 SECOND DRAFT (ii) To assess students’ generic skills (such as creativity, critical-thinking skills, communication skills, problem-solving skills and collaboration skills) through the use of a wide variety of tasks adopted in the learning process. 5.7 The SBA will contribute 20% of the total weighting of the public assessment of Senior Secondary Physics. 5.8 The SBA of Physics will be divided into two main components: practical related tasks and non-practical related tasks. The former refers to the practical work characteristic of physics, while the latter refers to non-practical related assignments and examinations which students are asked to carry out for the learning of the subject. 5.9 The aim of including non-practical related tasks is to broaden the scope of assessment in the SBA, and hence in the public assessment. The abilities of students in many different aspects can be duly recognised by awarding their achievements in a wide variety of tasks adopted in the learning process. The integration of curriculum, teaching and assessment will also be much enhanced. To this end, the assignments to be included in the SBA aim to cover one or more of the curriculum content areas and one or more of the aforementioned generic skills, which are embodied in the learning targets set out in the curriculum. Examples of assignments that can be used for assessment are: Critically read, analyse and report the works of some physicists in their contribution toward the understanding of the universe. Design a poster / pamphlet / web page advising on ways in which people can use energy more efficiently. Report scientific knowledge and concepts acquired after a visit to a power station or the Hong Kong Science Museum. Construct animation to illustrate the process of fission/fusion. 5.10 It should be noted that SBA is not an “add-on” element in the curriculum. The modes of SBA thus selected above are normal in-class and out-of-class activities suggested in the curriculum. The requirement and implementation of the SBA will take into consideration the wide range of abilities of students and will avoid unduly increasing the workload of both teachers and students. Detailed information on the requirements and implementation of the SBA and samples of assessment tasks will be provided to teachers in due course. 98 SECOND DRAFT Standards-referenced Approach 5.11 In the public assessment, a standards-referenced approach will be adopted for grading and reporting student performance. The purpose of this approach is to recognise the learning outcomes that the students have attained in the subject at the end of the 3-year senior secondary education. Each student’s performance will be matched against a set of performance standards, rather than compared to the performance of other students. Standards-referenced Approach makes the implicit standards explicit by providing specific indication of individual student’s performance. Descriptors will be provided for the set of standards at a later stage. 99 SECOND DRAFT Chapter 6 Effective Use of Learning and Teaching Resources 6.1 A subject curriculum and assessment guide will be published to support learning and teaching. The Guide will provide stakeholders with information on the rationale, curriculum aims, curriculum framework, learning and teaching strategies and assessment. In addition, it is anticipated that quality textbooks and related learning and teaching materials, aligned with the rationale and the recommendations of the curriculum, will be available on the market. 6.2 Resource materials that facilitate learning will be developed by Education and Manpower Bureau (EMB) to support the implementation of this curriculum. Tertiary institutions and professional organisations will be invited to contribute to the development of resource materials. Existing resource materials, such as “Physics World”, “Contextual Physics”, “Contextual Physics in Ocean Park”, “Using Datalogger in the Teaching of Physics” and “Enhancing Science Learning through Electronic Library”, published by EMB and various working partners will be updated to meet with the latest curriculum development. Furthermore, schools are encouraged to develop their own learning and teaching materials to meet the needs of their students, as necessary. Schools are also advised to adopt a wide variety of suitable learning resources, such as school-based curriculum projects, useful information from the Internet, the media, relevant learning packages and educational software packages. Last but not the least, experiences from various collaborative research and development projects, such as “Informed Decisions in Science Education”, “Assessment for Learning in Science”, “Infusing Process and Thinking Skills into Science lessons” and “Collaborative Development of Assessment Tasks and Assessment Criteria to Enhance Learning and Teaching in Science Curricula” are good sources of information for teachers. 100 SECOND DRAFT Chapter 7 Supporting Measures 7.1 To facilitate the implementation of the curriculum, professional development programmes will be organised for physics teachers. Listed below are the major domains of the professional development programmes to be provided. 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