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Balloon Fest Experiment Validation GloryBoyz, 2015 Members:
Frank Molina, MK Tagalicud, Matt Clark, Brandon Florentino Purpose: Many factors affect the rate at which an object will fall. Our experiment is to see if a larger and more powerful motor attached to the bottom of our CD case can actually affect the rate of how fast a parachute falls by adding more weight and putting more air into the parachutes at a faster rate. On the other hand, we are also testing if the ideal concept that all objects fall at the same rate due to gravity will prevail. Research: In the ideal conditions, the rate at which the force of gravity pulls down objects should be consistent regardless of the variations in the masses. In reality, however, objects will fall at different rates given the presence of multiple external factors such as the resistive force of drag and the distribution of force across varying surface areas. Other uncontrollable forces will also affect the flight path of each parachute depending on how the force is applied to them. For example, wind can come in contact at different angles at each parachute causing one to be derailed from the fastest rate of speed at which it could potentially be in. The air resistance could be greater for one balloon because of the motor’s presence. Furthermore, wind could be more impactful during one trial and not so much during another. Assuming the there is no air resistance or other external factors except drag, each parachute will fall with a force of : m * g (mass X acceleration) ~ 35.5 g X 9.8 m/sec^2 ~ 347.9 N minus the upward resistance of air into the parachute. The force done by the mousetrap on the release system thread will be stored as potential energy in the spring that will convert into kinetic energy as it it triggered. Thus, potential energy before being triggered will equal the total kinetic energy of the spring as it is released. Using the concept of torsion, you can find the force :
U=12kθ
^ 2
which would equal ∴U=0.5∗3.45∗π
2
≈
17.025 J.
Therefore, the force of the mousetrap, 17.025 J, should be greater than the tensile strength of the thread holding the parachute. Since the parachute can easily cut the rope, the force needed to break this piece of thread must equal less than 17.025 J. In addition, the light sensor is programmed to be sensitive enough that the LED flashlight of an iPhone can trigger but resistant enough that the sunlight doesn’t set it off too early. The configurations are specific to Arduino examples and altered enough for the purpose of the experiment: In addition, the phone bill will have been paid before the 15th of May and will be in full effect until June 15th so the issue of phone service will not be a problem: Conclusion: All equipment have been tested and bugs have been removed when practice experiments were practiced just as they would have been done at the actual Balloon Fest. For two hours, the teams practiced every step in the Procedures document in a timed fashion. As a result, flaws in the experiments and equipment were revised and improved repeatedly until everything was fully functional. At first the release system took too long, but a more efficient way using screws and thread solved the problem. A cover was needed to make sure sunlight would not affect the light sensor. And a tether to the main rope was installed to make sure the path flight will not be too unpredictable.