SCIENCE AND TECHNOLOGY CONCEPTS FOR MIDDLE SCHOOLS™ Changes to the Catastrophic Events Teacher’s Guide and the Catastrophic Events Student Guide and Source Book Since publication of the Catastrophic Events Teacher’s Guide and Student Guide, a component of the module kit—the Convection Tubes™ used in Lessons 4 and 5—has been redesigned. Changes to the product require revised instructions in the module’s printed materials, both for the teacher and student. This errata set includes the following: ■ For the Catastrophic Events Teacher’s Guide - revised pages 48–52, 59–61, 66, and 116. ■ For the Catastrophic Events Student Guide - revised pages 43–47 and 55–57. Photocopy and distribute these new instruction pages as needed. If you have any questions about these changes, or about the module in general, call Carolina’s product information staff at 1-800-227-1150 (8 am–5 pm ET, M–F), or email stcms@carolina.com. Carolina Biological Supply Company 2 7 0 0 Yo r k R o a d , B u r l i n g t o n , N o r t h C a r o l i n a 2 7 2 1 5 1-800-334-5551 w w w. c a r o l i n a . c o m 0209 LESSON 4 H E AT T R A N S F E R AND THE MOVEMENT OF MATERIALS FOR INQUIRY 4.1 For each student 1 completed copy of Student Sheet 3.1b: Interpreting a Data Table 1 copy of Student Sheet 4.1: Investigating the Temperature of Air For each group of 4 students 1 tote tray 2 Convection Tubes™ 1 120-mL plastic container of hot water (with screw-top lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 stopwatch 1 metal digital thermometer 1 ruler 1 paper towel 2 #16 rubber bands (23⁄8- × 1⁄16-in) 2 pieces of plastic wrap (approximately 14-cm square) MATERIALS FOR INQUIRY 4.2 For each group of 4 students 1 tote tray 2 Convection Tubes 1 120-mL plastic container of hot water (with screw-top lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 7.5-cm piece of plastic airline tubing (1⁄2-in diameter) 1 small funnel 1 punk stick 1 flashlight 1 small aluminum pan 1 ruler 2 paper towels 2 #16 rubber bands 2 pieces of plastic wrap Scissors 48 STC/MS™ C ATA S T R O P H I C E V E N T S AIR PREPARATION 1. Make a copy for each student of Student Sheet 4.1: Investigating the Temperature of Air. 2. Use Figure 4.2 and the following steps to set up two Convection Tubes for each group. For each Convection Tube, do this: A. Make certain that two aquarium thermometers are attached securely to the inside of each cylinder. B. Make certain that the plastic tubing (1⁄2-in diameter) is cut into approximately 7.5-cm lengths. Each group needs only one 7.5-cm piece of tubing. C. Attach the plastic tubing to the funnel and set this aside. Students will not connect the tubing and funnel to the base until Inquiry 4.2. 3. Set up the hot pot in a safe area of the room. Bring the water to a boil, and then let it simmer. If possible, prepare a thermos of hot water (approximately 60 °C). Fill one 120-mL container with hot water for each group right before the inquiry begins. For safety reasons, plan to cap each group’s container with a black lid. 4. If you do not have a freezer nearby, put the crushed ice in a cooler. Plan to set out one container of crushed ice at each group’s work area. Cap the container until students begin the inquiry. 5. Cut the plastic wrap. Include it in each group’s tray of materials at the distribution center or distribute it to each group during the lesson after students have observed moisture forming on the inside of the cylinders. LESSON 4 AND THE MOVEMENT OF AIR C. How do you think the temperature of the earth’s surface affects the temperature of air above it? (Use this question to assess students’ understanding of how surface temperature affects the temperature of air above it. Some students may already understand that a warm surface can give off heat to the air above it and that a cool surface can lower the temperature of the air above it. Most students will gain this understanding in the lesson.) Thermometers Nozzle Tube Funnel Base Figure 4.2 H E AT T R A N S F E R Assembling a Convection Tube. Do not attach the funnel and tubing to the base until Inquiry 4.2. Getting Started 1. Review with students the completed homework from Lesson 3, Student Sheet 3.1b: Interpreting a Data Table. Discuss answers to the questions in “Getting Started” in the Student Guide. (See Inquiry Master 3.1b: Interpreting a Data Table [Answer Key].) Answers are as follows: A. What was the temperature of Portland Parklands at 2:00 P.M.? (It was 26.5 °C.) B. How do you think this temperature might compare with the temperature of the Atlantic Ocean near Portland, Maine, at 2:00 P.M.? (It would be warmer than the temperature of the ocean.) D. How do you think the temperature of the air affects how air moves? (Use this question to assess students’ understanding that the temperature of air affects how it moves. Some students may already understand that warm air rises and cool air sinks.) 2. Let students know that in this lesson they will investigate how the temperature of the earth’s surface affects air temperature, air movement, and cloud formation. 3. Show students a Convection Tube. Have students brainstorm ways they might investigate this concept using this apparatus. Allow the discussion to be open-ended. Inquiry 4.1 Investigating the Temperature of Air PROCEDURE each student one copy of Student 1. Give Sheet 4.1. Have students read the question at the top of the student sheet. Discuss each step of the student sheet with the class. Point out that Table 1 is similar to the table in Lesson 3. the setup shown in TG 2. Demonstrate Figure 4.3 (SG Figure 4.1). As you do, review with students Procedure Steps 5 through 12 in the Student Guide. STC/MS™ C ATA S T R O P H I C E V E N T S 49 LESSON 4 H E AT T R A N S F E R AND THE MOVEMENT OF AIR students to complete Question 2 on 5. Ask the student sheet. Invite them to discuss their predictions with the class. students pick up all their materials 6. Have except the hot water. Have them practice reading the thermometers inside the cylinders. The number highlighted with green is the correct temperature. If two numbers that are not green are highlighted, students can average them. students have set up their materi7. When als, distribute hot water to each group. Students can then begin the inquiry following Procedure Steps 5 through 12 in the Student Guide. Hot water Figure 4.3 Crushed ice Setting up Inquiry 4.1 explaining that moisture will 3. Without form on the inside of the Convection Tube with hot water, tell students that they may need to clear the cylinders and bases if they become difficult to see through. (See Figure 4.4.) Refer students to SG Figure 4.2 and demonstrate how to do this. After clearing the Convection Tube, students have the option of covering the container of water with plastic wrap and securing it with a rubber band. students to answer Question 1 on 4. Ask Student Sheet 4.1. Then discuss as a class how they will set up their equipment to make it a fair test. (The following are examples of variables that will remain the same: amount of water in each container, amount of time each container of water is under the Convection Tube, and amount of time between temperature readings. The one variable that will change is the temperature of the water in each container.) 50 STC/MS™ C ATA S T R O P H I C E V E N T S Figure 4.4 Use a paper towel to remove moisture from the base of the Convection Tube. Use a paper towel attached to a ruler to remove moisture from the inside of the cylinder and base. LESSON 4 REFLECTIONS the answers to the questions in 1. Discuss Step 1 of “Reflecting on What You’ve Done” in the Student Guide. Suggested answers are as follows: A. How did the temperature of each container of water affect the temperature of the air above it? (The hot water heated the air directly above it. This means that the temperature of Thermometer B probably rose higher than the temperature of Thermometer A in the Convection Tube with the hot water. The cold water cooled the air directly above it. This means that in the Convection Tube with cold water, the cold water made the temperature of Thermometer B drop.) B. The movement of heat is called heat transfer. Describe the heat transfer between the container of hot water and the air. Describe the heat transfer between the container of cold water and the air. (Heat energy always moves from warm materials to cooler ones. Therefore, heat moved [1] from the warm water to the cooler air, which heated the air, and [2] from the warm air to the cooler water, which heated the water and cooled the air.) C. Under what conditions was it difficult to see through a cylinder? Why do you think this happened? (The inside of the tube with hot water “fogged” up because moisture formed on the inside of the Convection Tube. More condensation took place with hot water than with cold water because of greater evaporation from the container of hot water.) H E AT T R A N S F E R AND THE MOVEMENT OF AIR D. Why do you think covering the container helped to keep the cylinder clear? (The plastic reduced evaporation by blocking the escape of water vapor.) students know that during Inquiry 2. Let 4.2, they will investigate how the temperature of the air affects how air moves. NOTE If you are teaching this lesson in two 45-minute periods, this is a good stopping place. Assign the homework for Period 1. Inquiry 4.2 Investigating How Warm Air and Cool Air Move PROCEDURE students know the purpose of this 1. Let investigation: to find out how the temperature of a surface affects the movement of the air above it. Have students record this purpose in their notebooks in the form of a question. Ask students for ideas on how they might explore this question using the Convection Tube. lighting the punk, demonstrate 2. Without the setup shown in TG Figure 4.5 and SG Figure 4.3. As you do, review Procedure Steps 4 through 9 in the Student Guide. students to predict how the tem3. Invite perature of a surface affects the way in which the air above it moves. After students record their predictions in their notebooks, have them share their ideas with their group or the class. students pick up their materials and 4. Have begin the investigation. Turn off the class- STC/MS™ C ATA S T R O P H I C E V E N T S 51 LESSON 4 H E AT T R A N S F E R AND THE MOVEMENT room lights. Then light each group’s punk at its work area. (See Figure 4.6.) Hold the lighter close to the punk for several seconds until it ignites completely. Then have a student blow it out. The punk will smolder. OF AIR students finish the investigation, 5. When ask them to clean up. Students should dip the tip of the punk in a container of water to douse it. They should then cut off the tip. Remind students not to soak the punk or to wet more than just the tip, because the next class will also use the punk. SAFETY TIP Do not carry the lighted punk across the room. Light each group's punk at its work area. Also tell students to be careful when working with the burning punk. They should not walk around the room while holding it. Figure 4.6 Figure 4.5 52 STC/MS™ C ATA S T R O P H I C E V E N T S Lighting the punk Setting up Inquiry 4.2 LESSON 5 which it dissipates and a new cell replaces it. Squall lines can last for hours. They are capable of spawning tornadoes. A storm cell dissipates when gusts of cold air blow the rain down and outward from the base of the cloud. The downward movement blocks warm air from continuing to rise. Soon the rain slows and stops, and the thunderstorm spreads out and dies. Thunderstorms: Part of Earth’s Cooling System Because students often focus on the negative impact of storms, it is important to help them understand that thunderstorms are part of the earth’s natural cooling system. Thunderstorms move heat from the earth’s surface to high altitudes, where the heat is released into the atmosphere. Thunderstorms also cleanse the air and carry life-sustaining water from seas and lakes to dry land. In this lesson and throughout the rest of the module, the constructive effects of natural catastrophic events, as well as the destructive ones, are built into the classroom discussions. Reading Selections Three extended reading selections appear in Lesson 5 of the Student Guide. The first, “Why Does the Wind Blow?” discusses land and sea breezes, global winds, and the jet stream. It is accompanied by a brief selection entitled “What Are Monsoons?” “Weather Fronts,” a second extended reader, contains information on cold fronts, warm fronts, and occluded fronts. “Trouble in Tornado Alley” focuses on the tornadoes that devastated several states in the Central Plains in May 1999; it also contains advice on what to do in case of a tornado. Accompanying the reader on Tornado Alley, “Waterspouts” briefly describes this type of storm, which is similar in many ways to tornadoes. CONVECTION CURRENTS IN THE AIR MATERIALS FOR LESSON 5 For the teacher 1 lighter Cooler 1 plastic tubing cutter Hot pot Newsprint, transparency, or chalkboard For each student 1 copy of Student Sheet 5.1a: When Air Masses Meet 1 copy of Student Sheet 5.1b: Convection on the Earth For each group of 4 students 1 tote tray 2 Convection Tubes 1 7.5-cm piece of plastic tubing (1⁄2-in diameter) 1 flashlight 1 120-mL plastic container of hot water (with screw-top lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 tea candle 1 punk stick 1 small aluminum pan Scissors PREPARATION 1. Make one copy of Student Sheet 5.1a: When Air Masses Meet and Student Sheet 5.1b: Convection on the Earth for each student. Student Sheet 5.1b will be used as an assessment. Plan to assign the sheet for homework or to have students complete it in class. 2. Prepare the Convection Tubes for this lesson. For each group, connect two Convection Tubes by attaching the 7.5cm piece of tubing to each base’s nozzle, as shown in Figure 5.1. Make sure each nozzle is completely inserted into the piece of tubing. STC/MS™ C ATA S T R O P H I C E V E N T S 59 LESSON 5 CONVECTION CURRENTS IN THE AIR Getting Started 1. Invite a student volunteer to recap the results of Inquiry 4.2: Investigating How Warm Air and Cool Air Move. Review with students how a surface can heat or cool the air above it and how the temperature of air affects the way it moves. 2. Ask students to think back to the reader “Air Masses,” in Lesson 4. Where do they think air masses with different temperature and humidity conditions are most likely to meet in the United States? Use this question to assess students’ understanding of how tornadoes form. Inquiry 5.1 Investigating the Effects of Colliding Air Masses Candle Figure 5.1 Crushed ice Two connected Convection Tubes 3. If you do not have access to a freezer, put the crushed ice in a cooler. At the beginning of each class, set out one full 120-mL plastic container of crushed ice for each group. Cap each container to prevent spilling. 4. Set up a hot pot of water. You can distribute hot water to each group as students request it. 5. Plan how you will record questions and predictions. You can use newsprint, an overhead transparency, or a chalkboard. 60 STC/MS™ C ATA S T R O P H I C E V E N T S PROCEDURE Student Sheet 5.1a. Ask stu1. Distribute dents to read the question at the top of the student sheet: What happens when two of the same—and then different—air masses meet? Let students know they will investigate this question during the inquiry. the class a set of materials for 2. Show one group, including the connected Convection Tubes. Elicit from students possible setups they could develop, using Table 1 and the available materials, to test the question on Student Sheet 5.1a. The following is a list of possible setups: A. Two cold moist air masses meeting: containers of crushed ice under both tubes B. Two warm moist air masses meeting: containers of hot water under both tubes LESSON 5 C. A cold moist air mass and a hot dry air mass meeting: container of crushed ice under one tube and tea candle (or container of hot water) under the other. students record on Student Sheet 3. Have 5.1a the materials and procedures they will use for each of these setups. students which variables they will 4. Ask keep constant in each setup and which variable they will manipulate. Have students record their ideas on Student Sheet 5.1a. each group to predict what will 5. Invite happen during each part of the investigation. Have students record their group’s predictions for each setup on Table 1 of the student sheet. 6. Review with students Procedure Step 6 in the Student Guide. Discuss SG Figure 5.2. Students should discover on their own that they must introduce the smoke into the cold cylinder, since cold air sinks. Review the Safety Tips. CONVECTION CURRENTS IN THE AIR each group to collect and set up its 7. Ask materials and begin the investigation. Light each group’s punk stick when students are ready. Turn off the classroom lights when students turn on their flashlights so that the smoke will be visible. Light the tea candle only when a group is ready to complete the third setup. students complete their investiga8. When tions, have them blow out all tea candles and douse all punk sticks. Remind them to dip only the tip of the punk in water. Cut off the wet tip with scissors. Have each group prepare for the next class by refilling its beaker with crushed ice. REFLECTIONS students to discuss their observations 1. Ask and answer these questions: A. What did you observe when both tubes contained air with the same temperature and humidity conditions? Why do you think this happened? (The air did not move much, since the general circulation of the air was weak.) SAFETY TIPS Roll up loose sleeves and tuck in loose clothing. Tie back long hair. Do not let the burning punk touch the cylinder. The plastic cylinder will melt if it does. Light each group’s candle for them, and only when they are ready to use it. B. What did you observe when the tubes contained air with different temperature and humidity conditions? Why do you think this happened? (The air moved quickly throughout both tubes. Air in the cold tube sank and moved through the plastic tubing to the warm tube to replace its rising, warm air. When the cold air got warmer, it rose as well.) Do not reach across an open flame. Remind students not to leave the candle under the plastic cylinder for longer than 1 minute. The plastic will get hot. C. On the basis of your results from Lessons 4 and 5, under what conditions do you think winds and rotating storms might form? (When air masses of different temperature and humidity conditions meet, turbulent air circulation and unsettled weather are the result.) STC/MS™ C ATA S T R O P H I C E V E N T S 61 LESSON 5 CONVECTION CURRENTS IN THE AIR Name: Class: Date: Student Sheet 5.1b Convection on the Earth Directions After you have finished Inquiry 5.1, complete Questions 1 through 3 here. 1. Think back to Inquiry 5.1. Draw a punk stick, smoke, and arrows on the Convection Tubes to show the movement of air. Then, in the space below the illustration, explain why the air moves like this. Candle Crushed ice Explanation: (continued) 66 STC/MS™ C ATA S T R O P H I C E V E N T S 2000 National Academy of Sciences LESSON 8 STORMS ASSESSMENT Inquiry Master 8.1b (continued) Question 14 Use the illustration of the Convection Tubes to answer Question 14. 14. Tara connects two Convection Tubes. She adds smoke to one cylinder. The smoke immediately sinks to the bottom of the cylinder and moves into the second cylinder and then rises. Which of the following statements describes Tara’s setup? A. She connected two hot cylinders. She added smoke at the top of one hot cylinder. B. She connected two cold cylinders. She added smoke at the top of one cold cylinder. C. She connected one hot and one cold cylinder. She added smoke at the top of the cold cylinder. D. She connected one hot and one cold cylinder. She added smoke at the top of the hot cylinder. Question 15 Use the illustration of the soil and water investigation to answer Question 15. 15. Study the setup for an investigation in which soil and water are being heated. What changes would you make to the setup to make it a fair test? A. Put equal amounts of soil and water in each beaker. B. Place the beakers of soil and water equal distances from the lamp. C. The setup is correct. D. I would do both A and B. Water Soil (continued) 116 STC/MS™ C ATA S T R O P H I C E V E N T S 2000 National Academy of Sciences moves? You will investigate these ideas in Lesson 4. Then, in Lesson 5, you will look at what happens when air masses of different temperatures meet. Getting Started over your homework from Lesson 3, 1. Go Student Sheet 3.1b: Interpreting a Data Table, with your teacher. As you do, think about the following: A. What was the temperature of Portland Parklands at 2:00 P.M.? B. How do you think this temperature might compare with the temperature of the Atlantic Ocean near Portland, Maine, at 2:00 P.M.? C. How do you think the temperature of the earth’s surface affects the temperature of air above it? D. How do you think the temperature of the air affects how air moves? Discuss your ideas with the class. this lesson, you will investigate how the 2. In temperature of a surface affects air tem- MATERIALS FOR INQUIRY 4.1 MATERIALS FOR INQUIRY 4.2 For you 1 completed copy of Student Sheet 3.1b: Interpreting a Data Table 1 copy of Student Sheet 4.1: Investigating the Temperature of Air For your group 1 tote tray 2 Convection Tubes 1 120-mL plastic container of hot water (with screwtop lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 piece of plastic tubing 1 small funnel 1 punk stick 1 flashlight 1 small aluminum pan 1 ruler 2 paper towels 2 rubber bands 2 pieces of plastic wrap Scissors For your group 1 tote tray 2 Convection Tubes™ 1 120-mL plastic container of hot water (with screwtop lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 stopwatch 1 digital thermometer 1 ruler 1 paper towel 2 rubber bands 2 pieces of plastic wrap perature, air movement, and the formation of clouds. Your teacher will show you a Convection Tube™. Brainstorm with your class ways in which you might use the tube to explore this interaction. STC/MS™ C ATA S T R O P H I C E V E N T S 43 LESSON 4 H E AT T R A N S F E R AND THE MOVEMENT OF Inquiry 4.1 Investigating the Temperature of Air PROCEDURE over Student Sheet 4.1: 1. Look Investigating the Temperature of Air as your teacher discusses it. Read the question at the top of the student sheet. You will complete the student sheet as you conduct Inquiry 4.1. as your teacher demonstrates 2. Observe the setup and Steps 5 through 12 of the Procedure. Review Figures 4.1 and 4.2 with your teacher at this time. AIR of the crushed ice. Write the temperatures for cold and hot water in Table 1 on the student sheet. you place each container of water 8. Before (without its lid) under a Convection Tube, record the starting temperatures of both thermometers in both cylinders on Table 1 of the student sheet. Write them across from Time 0:00. (Thermometer A is the top thermometer.) your stopwatch at zero. Place the 9. Set container of hot water under one Convection Tube. Place the container of cold water under the other Convection Tube, as shown in Figure 4.1. Then start the stopwatch. would you make this investiga3. How tion a fair test? List your ideas under Question 1 on Student Sheet 4.1. a prediction, then record it 4. Make under Question 2 on the student sheet. Discuss your prediction with your class. your materials. With your 5. Collect group, practice reading the thermometers inside the cylinders. The number on the thermometer highlighted with green is the correct temperature. If two numbers that are not green are highlighted, you can average them. not been done for you, fill 6. Ifoneit has plastic container with hot water and one with ice water (crushed ice). the digital metal thermometer to 7. Use measure the temperature of the hot water. Also measure the temperature 44 STC/MS™ C ATA S T R O P H I C E V E N T S Hot water Figure 4.1 Crushed ice Place a container of water under each Convection Tube. LESSON 4 the changes in temperature in 10. Record each Convection Tube every minute for 3 minutes in Table 1. If the temperature goes higher than the thermometer’s highest temperature, you can record 30+ °C on your data table. (Do not touch the outside of the cylinder. Your hand may affect the temperature readings.) 11. If it gets difficult to see inside the Convection Tube, use a paper towel to remove moisture from the base. Attach a H E AT T R A N S F E R AND THE MOVEMENT OF AIR paper towel to a ruler with a rubber band and use this device to clear the cylinder and base, as shown in Figure 4.2. After clearing the Convection Tube, you can cover your containers of water or ice with plastic wrap and secure the wrap with a rubber band. 12. Clean up. REFLECTING ON WHAT YOU’VE DONE these questions; then discuss your 1. Answer results with the class. A. How did the temperature of each container of water affect the temperature of the air above it? B. The movement of heat is called heat transfer. Describe the heat transfer between the container of hot water and the air. Describe the heat transfer between the container of cold water and the air. C. Under what conditions was it difficult to see through a cylinder? Why do you think this happened? D. Why do you think covering the container helped to keep the cylinder clear? “What’s the Forecast?” on pages 2. Read 50–53 before Inquiry 4.2 begins. Figure 4.2 Clearing the Convection Tube STC/MS™ C ATA S T R O P H I C E V E N T S 45 LESSON 4 H E AT T R A N S F E R AND THE MOVEMENT OF Inquiry 4.2 Investigating How Warm Air and Cool Air Move PROCEDURE the purpose of this investigation 1. Record in your notebook. Write it in the form of a question. Then share it with your group or class. Also share with the class your ideas on how to test this question. teacher will demonstrate how to do 2. Your this investigation. Follow along using Procedure Steps 4 through 9. AIR a prediction. How do you think air 3. Make will move above a hot surface? How do you think air will move above a cold surface? Record your prediction in your notebook. Discuss your ideas with your group or class. up your materials. Set up the 4. Pick Convection Tubes with hot and cold water, as you did in Inquiry 4.1. You will not be recording temperature changes in this investigation. Use the ruler and paper towel to clear the cylinder or cover the containers with plastic wrap. the funnel and tubing to the 5. Attach Convection Tube with cold water. (It is very important that you begin with the cold water.) you are ready, ask your teacher to 6. When light your group’s punk stick. Immediately blow it out and hold the smoking punk over the aluminum pan, as shown in Figure 4.3. Hold the funnel at an angle over the punk so the smoke goes inside. Do not touch the funnel with the burning punk. SAFETY TIP Figure 4.3 Putting smoke into the Convection Tube 46 STC/MS™ C ATA S T R O P H I C E V E N T S Follow safety precautions when working with a burning punk. Do not walk around the room with the punk while it is burning. LESSON 4 teacher will turn off the classroom 7. Your lights. Use your flashlight to see the smoke particles moving. Hold the flashlight behind the Convection Tube and then at the top of it. Do not cover the opening of the Convection Tube. (See Figure 4.4 [A] and [B].) Kneel down so you can see the smoke at eye level as it enters the Convection Tube. Talk to your partners about how the smoke moves. the tubing and funnel to the 8. Move Convection Tube with hot water. (One H E AT T R A N S F E R AND THE MOVEMENT OF AIR continue to hold the burning punk.) Clear the cylinder with the ruler and paper towel if needed. Place the punk under the funnel to add smoke to the Convection Tube with hot water. Observe. Use the flashlight to view the smoke. you have finished observing the 9. When Convection Tube with hot water, clean up. Carefully dip just the tip of the punk into a container of water. This will stop the tip from smoldering. Then cut off the wet tip. member of your group should carefully Figure 4.4 (A) Shine the flashlight from behind the Convection Tube to view the air as it enters the cylinder. (B) Hold the flashlight at the top of the Convection Tube to see the smoke throughout the (A) (B) cylinder. Do not block the opening of the cylinder. STC/MS™ C ATA S T R O P H I C E V E N T S 47 Getting Started back to Lesson 4. What did you dis1. Think cover about how the temperature of air affects the way air moves? Discuss this with your class. back to the reading selection, “Air 2. Look Masses,” on page 49 in Lesson 4. Where do you think air masses with different temperature and humidity conditions are most likely to meet in the United States? MATERIALS FOR LESSON 5 For you 1 copy of Student Sheet 5.1a: When Air Masses Meet 1 copy of Student Sheet 5.1b: Convection on the Earth For your group 1 tote tray 2 Convection Tubes 1 piece of plastic tubing 1 flashlight 1 120-mL plastic container of hot water (with screwtop lid) 1 120-mL plastic container of crushed ice (with screw-top lid) 1 candle 1 punk stick 1 small aluminum pan Scissors STC/MS™ C ATA S T R O P H I C E V E N T S 55 LESSON 5 CONVECTION CURRENTS IN THE AIR Inquiry 5.1 Investigating the Effects of Colliding Air Masses will you keep the same in each 4. What setup? What will you change during each test? Write down your ideas on Student Sheet 5.1a. PROCEDURE 1. Collect one copy of Student Sheet 5.1a: When Air Masses Meet. Read the question at the top of the student sheet: What happens when two of the same— and then different—air masses meet? You will investigate this question during the inquiry. do you think will happen when 5. What cold, moist air meets cold, moist air? What do you think will happen when warm moist air meets warm moist air? What will happen when cold moist air meets hot dry air? Discuss your predictions with your group. Record what you think will happen in the Predictions column in Table 1 on your student sheet. at one set of 2. Look connected Convection Tubes and the materials for each group. Then look at Table 1 on Student Sheet 5.1a. What are some ways you might set up this equipment to investigate the question in this inquiry? Discuss this with your class. One suggested setup is shown in Figure 5.1. your student 3. On sheet, make a list of the materials you will use and the procedures you will follow to test each setup. Be prepared to share your ideas with the class. Candle Figure 5.1 56 STC/MS™ C ATA S T R O P H I C E V E N T S Connected Convection Tubes Crushed ice LESSON 5 6. Review with your teacher the following points, which you should keep in mind while you work: A. Keep the Convection Tubes connected at all times. B. Do not record any temperature changes in this lesson. C. Introduce smoke into the top of the cylinder, as shown in Figure 5.2. IN THE AIR SAFETY TIPS Roll up loose sleeves and tuck in loose clothing. Tie back long hair. Do not let the burning punk touch the cylinder. The plastic cylinder will melt if it does. Do not ask your teacher to light your candle until you are ready. you begin, review Safety Tips with 7. Before your teacher. and set up your materials. Begin 8. Collect the investigation. Discuss your observa- Do not reach across an open flame. tions with your group as you work, and record them on your student sheet. For each setup, remember the procedures your group developed. Use your flashlight to see the smoke. Do not leave the candle under the plastic cylinder for longer than 1 minute. The plastic will get hot. you have finished testing 9. When all three conditions, clean up. Put out the burning punk by dipping just the tip of it in a cup of water. Cut off the wet tip with the scissors. Refill your container with crushed ice for the next class. Figure 5.2 CONVECTION CURRENTS Use the punk stick to introduce smoke into the top of the tube. STC/MS™ C ATA S T R O P H I C E V E N T S 57
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