Egg Car Collision Project

Transcription

1 Name Date Egg Car Collision Project Objective: To apply your science knowledge of momentum, energy and Newton s Laws of Motion to design and build a crashworthy vehicle. Introduction: The popularity of the automobile has brought with it some undesirable effects. Among these are air pollution, traffic jams, and traffic fatalities. Each year, thousands of people are injured or killed as a result of automobile accidents. Because of this, automotive safety design has become a major part of the auto industry. Safety engineers have concluded that passenger restraints are one safety device that could reduce automobile fatalities dramatically. Seat belts and shoulder harnesses keep passengers from being thrown from the vehicle or bounced around inside of the vehicle causing injury. Another important category of safety devices are energy absorbing devices. They absorb or cushion the impact of a collision. Some examples of energy absorbing systems include airbags, bumpers and crumple zones. The combination of passenger restraint systems and energy absorbing devices designed into a vehicle can help to save many lives. This activity will allow you to assume the role of a safety engineer as you design, install, and test various safety devices for a crash vehicle. Design Brief: As a mechanical engineer employed for a major automobile manufacturer you have been assigned the task of designing and installing safety devices for a new test vehicle. The vehicle must be aerodynamically designed and it must be able to roll along a test ramp and into an immovable object at the end of the track (e.g., the wall) while protecting the passenger (a raw egg) from injury. Materials: (For the entire class) - Test ramp (rain gutter) - triple beam or digital balance - Stop watch - meter stick - Plastic egg (crash-test dummy) - scissors - glue - markers/crayons for decorations Materials: (For each team of two) - 4 sheets of paper (maximum) - 4 cardboard wheels - 1 raw egg (simulated "live" passenger) - 1 zip lock bag (body bag) - drinking straw (for axle that connects one wheel to the next)

2 Egg Car Vocabulary: Write a complete sentence in your own words describing each term. You may use your textbook and your notes. 1. Speed- 2. Force- 3. Inertia- 4. Acceleration - 5. Friction - 6. Momentum 7. Potential Energy - 8. Kinetic Energy -

3 Rules and Requirements: 1. There can be no physical contact between you and your car once the vehicle has been released on the track. 2. The design must allow for easy removal and inspection of the egg. You may test your vehicle with a plastic egg before receiving your real egg on competition day. 3. Repairs requiring additional materials will not be allowed once the competition has begun. 4. All vehicles must display the following: a. vehicle's name b. builders names c. vehicle's width and length in cm d. vehicle's mass (without egg), in grams Pre-Construction Thought Questions: Answer the following questions using complete sentences. 1. How will the mass of the car affect its speed? 2. What can I add to my car to make the egg safe when the car hits the wall? 3. Should the egg be able to move within the car, or should it be held immobile? 4. How can the car be designed to easily remove and inspect the egg? 5. List any design features that will maximize your car s overall speed and crashworthiness.

4 Egg Car Plan Sheet In the space below, design your egg car. Draw both a side view and a top view. Label ALL parts of your vehicle. Include the measurements of all sides. Maximum Width 6.5 cm Maximum Length 16.5 cm Maximum Mass 40 grams (without egg) SIDE VIEW: TOP VIEW:

5 Competition Day! 1. You should have constructed your egg car by this time. 2. Before racing you need to document the dimensions of your car (length, width, and mass). 3. Record this data into Race Data Table # 1 below. 4. Take your car to the race track where you will test your vehicle. 5. Place your car at the top of the ramp and release. 6. Use your stopwatch to determine the time it takes for your vehicle to crash into the wall. 7. Measure the distance traveled. 8. Calculate the speed of your vehicle (Remember: Speed = distance/time) 9. Record this data into Race Data Table # 2 below. 10. Inspect and determine the condition of your egg. 11. Repeat for the remaining trials. 12. Construct a bar graph or line graph representing the speed of your vehicle for each trial. Remember to give your graph a title and label your x and y axis. 13. Complete the Post Lab Thought Questions and Class Data Summary. Race Data Table # 1 Length of car Width of car Mass of car (without egg) Mass of car (with egg) cm cm g g Race Data Table # 2 Trial Distance (m) Time (s) Speed (m/s)

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7 Post-Race Thought Questions: Answer the following questions using complete sentences. (3-5 sentences each) 1. Explain what you were investigating in this project and why it is important. 2. Describe the problems you encountered during the design/construction process and how you solved them. 3. Did your car perform as well as you expected for both speed and crashworthiness? What problems, if any, did you encounter during your crash test? 4. Describe the strengths and weaknesses of your design. 5. Considering all the cars in your class, which design features produced the highest speeds?

8 6. Considering all the cars in your class, which design features produced the fewest cracked eggs? 7. Did the car with the greatest speed also have the greatest momentum? Explain how a slower car can have more momentum than a faster car. 8. Discuss how you would modify your car to improve its performance in terms of both speed and crashworthiness. Class Data Summary Speed of the fastest car in the class Car with the most mass (including the egg) Total number of cars crashed Number of broken eggs Number of unbroken eggs