Mousetrap Race Car

Rules

1. The device must be powered by a single mousetrap.
2. You may only drill holes to mount the mousetrap to the frame and a mousetrap’s spring can be removed only to adjust the length of its lever arm.
3. The only energy, kinetic or potential, that your project can have at the start is what is stored in the mousetrap.
4. The spring from the mousetrap must not be compromised or changed in any way, shape, or form. You may design your project to switch out your spring to ensure that it did not lose any energy in all of your test runs. Push starting a vehicle is added energy and is not allowed.
5. The spring cannot be wound more than its normal travel distance of 180 degrees.
6. The vehicle must steer itself.?If a vehicle hits a wall and stops, then that is your total distance.
7. We are measuring Displacement and not Distance: https://www.physicsclassroom.com/class/1DKin/Lesson-1/Distance-and-Displacement
8. Your entire vehicle must be behind the starting line and the distance will be measured from the starting line to the point of the vehicle that was closest to the start line at the time of release.

Requirements

1. 4 sketches of different design ideas
2. 2 full-size detailed drawings of the final design choice from two different angles
3. Finished vehicle properly decorated and named
4. Journal of your process

Grading

Option 1 - Speed Rubric (20ft or 609.6cm):

Sub 7s = 100/100

7-8s = 95/100

8-9s = 90/100

9-10s = 80/100

10-11s = 70/100

11s> = -3 point per 0.5s taken

Option 2 - Distance Traveled Rubric:

2100cm+ = 100/100

1800-2099 = 95/100

1500-1799 = 90/100

1000-1499 = 85/100

900-999 = 80/100

750-899 = 75/100

500-749 = 70/100

<500 = 65/100

Kit vs Upcycle:

<50% Kit = 1.0 x grade

~75% Kit = 0.8 x grade

100% Kit = 0.5 x grade

Write-up

Your responses to the following topics should be typed in complete sentences.? This is a cumulative look at many of the physics concepts we have covered and you must prove to me that you know what you are talking about.?I expect you to use the vocabulary we have discussed in class rather than vague, everyday language.

• State each of Newton’s Laws and explain how each law applies to the motion of your race car.? Consider the forces involved during the beginning, middle, and end of your race car’s run.
• Describe how energy was conserved during your race car’s run.? How were potential and kinetic energy involved?? Which forms of energy were involved and how??
• Describe the two main simple machines that make up your race car.? What class of lever was used?? Discuss the ideal mechanical advantage of each simple machine (calculations optional).?Did you use the machines to multiply force or distance??How did these concepts influence the design you chose?
• Summarize what you learned through the process of building and racing your race car.? Be sure to discuss any problems you encountered and how you solved them.? What were your car’s strengths and weaknesses?? What changes would you make to your car in the future and why?
• You will maintain a detailed journal showing that you have tested your car, and considered how to improve their results. There must be at least 8 entries that discuss the test, the result, and thoughts for improvements.
• There should be a section that identifies what you feel are the 5 most important points in constructing a mousetrap race car.

Questions

1. What friction is present? What problems related to friction did you encounter and how did you solve them?
2. How many wheels does your car have? What factors did you take into account to decide the number of wheels?
3. What materials did you use in each axle and wheel? Why did you choose the size wheels that you did?
4. Explain how Newton's first and second laws apply to your car.
5. Discuss the effect of the length of the lever arm - could it be too large? Too small? Does this affect the power of your car? Explain.
6. How did the center of mass of your vehicle factor into your overall performance?
7. What factors, including distribution of weight, did you take into consideration with the overall design of your car? How does this relate to cars that you see on the road?
8. Discuss the major problems encountered in the performance of your car and what did you do to solve them.

?Feel free to add your spin in the comments!        

Quick hints for better performance

1. Reduce friction.
2. Every sound the car makes is energy lost.?
3. Use lightweight materials.
4. Amount of rotational inertia depends on the goal of the car.
5. Test the lever arm length and wheel size to determine the best for your type of car.
6. Experiment early and often.
7. Real World Physics Problems