Canyon Physics Egg Hurling Competition
Objective:
The object is to create and construct a device that will protect an uncooked hen’s egg while it is hurled 50-100 feet by the Physics Trebuchet. This competition is a physical test of your knowledge of impulse, momentum, kinetic energy, potential energy, and work. Scoring favors successful designs, so make sure your egg survives!
Warning:
In order to participate in the competition and receive a score, your project must conform to all of the rules spelled out below when it is turned in.
Double-check every rule before you turn in your project!
General Rules for the Competition:
- Devices will be clearly marked with name and period for identification before being submitted. No name = zero points!
- You may use any commonly available materials, with the exception of popcorn, “bubble plastic”, foam rubber, and other foamed materials (Styrofoam, plastic “peanuts”, sponges, etc.). If in doubt about a material, ask!
- Mr. Lyle will provide large AA Eggs.
- The device is a container, not an exercise in wrapping. The egg should be inserted and removed through a door or hatch as a passenger would enter and exit a vehicle.
- No parachutes will be used. Balloons may be used only inside the device as padding. Small drag-inducers such as streamers or fins may be used for orienting the device during its flight.
- The egg will be inserted in the device immediately before the hurl and removed immediately after the hurl. No more than 15 seconds will be required for insertion or removal. Only the owner may insert/remove the egg.
- Maximum device mass (without egg) will be 200g (0.44 lb.).
- Each device will have a 25 inch string tether attached by which the device will be hurled. Suitable string will be provided by Mr. Lyle. The string will be subjected to a large force (approximately 20 pounds), so it must be very securely fastened to the device. If the string tears loose the project does not meet specifications.
- When being hung by its tether, the device must pass through a 15cm diameter (6 in. diameter) opening without touching and be less than 60cm (24 in.) long. After being hurled, the device may deploy wings, rotors, etc that exceed these dimensions, but keep in mind that the device will then be moving at high speed!
- Students may work together, but each student will submit a device for testing.
- Devices will be submitted by the end of 7 th period Friday, December 14 th. They will be kept in the K-core for weighing and evaluation.
- Devices will be hurled during your class’s final exam period, weather permitting. First period classes will meet at 7:00AM on the first and second final exam days
- Devices that violate the spirit of the competition will be disqualified at the instructors’ discretion. Remember, the objective is to construct a device, not merely modify a found item. For example, removing the cardboard roll from a roll of toilet paper does not qualify as a constructed project.
Scoring will be based upon the success of the device and by its empty weight. The competition will be among all the students in the Conceptual and AP Physics classes. The lightest successful device will be assigned a score of 100, while the heaviest unsuccessful device will receive a score of 70. The lighter devices will earn the highest scores, and all successful devices will be scored higher than unsuccessful devices. Only the first hurl attempt will count for scoring purposes. Devices that deviate from the competition rules will be scored below all conforming devices.
Suggestions:
To protect the egg, you must minimize the force applied and prevent the formation of concentrated loads on its surface. The egg will have a lot of kinetic energy, so you have to maximize the distance over which the egg decelerates in order to minimize the force that causes that deceleration. Having the egg rebound isn’t such a good idea! Pay close attention to orienting your device during its flight. You can be sure that it will be jarred sideways as it is hurled, so you can’t depend on it to remain straight on its own. Remember, the center of mass must be forward of the center of pressure so "fins are your friends!"
The hurl will be made in the “real world,” so make sure that your container is able to cope with whatever winds, obstacles, uneven landing surfaces, and other random events might befall it. No whining!
