Mouse Trap Cars

MOUSE TRAP CARS

You will build an originally designed vehicle powered solely by the energy of one standard-sized mousetrap.

A very popular method of propulsion is to tie one end of a string to the arm (or an extended lever arm) on the mousetrap and the other end to the axle. By winding the string around the axle, the mousetrap's spring, when released, pulls on the string causing the wheels to turn and thus making the car move (there are, however, other creative ways to convey power from the mousetrap to the car).

OBJECTIVES The objective of this project is to... 1. Build a vehicle powered solely by the energy of one standard-sized mouse trap that will travel a minimum of 3 meters under it's own power 2. By definition, a vehicle is a device with wheels or runners used to carry something (e.g., car, bus, bicycle or sled). Therefore, launching a ball, (e.g., marble) from the mousetrap will be ruled illegal.

The project consists of 5 phases:  Mousetrap Car Design  Procurement of parts - Pass CHECKPOINT 1  Mousetrap Car Construction - Pass CHECKPOINT 2  Mousetrap Car Performance Evaluation - Race day.  Mousetrap Car Physics Analysis (Report)

All designs must follow the DESIGN INSTRUCTIONS.

Regulations 1. The device must be powered by a single Victor brand . Other brands may be used if permitted. 2. The mousetrap can not be physically altered except for the following: 4 holes can be drilled only to mount the mousetrap to the frame and a mousetrap's spring can be removed only to adjust the length of the lever arm. 3. The device cannot have any additional potential or kinetic energy at the start other than what can be stored in the mousetrap's spring itself. (this also means that you cannot push start your vehicle.) 4. The spring from the mousetrap cannot be altered or heat treated. 5. The spring cannot be wound more than its normal travel distance of 180 degrees. 6. Vehicles must be self-starting. Vehicles may not receive a push in teh forward direction or side direction. 7. The vehicle must steer itself. Measurements of distance will not measure the total distance traveled only the displacement distance. MOUSE TRAP CARS

8. Racers can not receive a running start and must start as close as possible to the start line. Time of run will begin when any part of the vehicle passes over the start line and will end when the racer comes to a complete stop. 9. Distance will be measured from the front of the tape at the starting line to the point of the vehicle that was closest to the start line at the time of release. 10. The instructor has the final decision as to the appropriateness of any additional items that might be used in the construction of the racer. 11. The race track will be a non-carpeted hallway. 12. Each contestant will be given three attempts

DESIGN INSTRUCTIONS 1. The vehicle must be powered by a single “Victor” or "Tomcat" brand mousetrap or equivalent (no rat traps allowed). You are not allowed to "heat treat" the spring to enhance tensile strength. 2. You have complete design freedom concerning vehicle size, vehicle weight, and materials used (except for the mouse trap "engine"). 3. CAR-KITS PURCHASED AT A HOBBY STORE OR ON-LINE ARE ABSOLUTELY PROHIBITED. The intent of this project is for you to research, design, and build your own car from "scratch" i.e. from individual components you have purchased, already have on hand at home or made. Please be aware that I am confident in my ability to identify purchased kits. Parts from toys (Example: tires from models, K'NEX parts, Erector Set parts, etc) are allowed if prior approved either before or at checkpoint 1. 4. You will not be permitted to "push start" your vehicle i.e. upon release, your vehicle must start moving on its own. 5. Only final displacement will be measured; "total distance traveled" does not count (i.e. the straighter the travel line, the better your grade will be). 6. Displacement will be measured from the starting line position to the front-most part of the vehicle at its final resting point. 7. Your goal is 10 meters or more. All cars must achieve a minimum of 3 meters displacement. Please examine the grading rubric (see link below); car performance is a major part of your project grade so test your design, make improvements and then test some more! MOUSE TRAP CARS

PHYSICS ANALYSIS OF YOUR PROJECT Answer the following questions completely (complete sentences and include formulas, diagrams, data tables and/or calculations where appropriate). Your answers must be submitted as a typed report, on your WIKI page or as a google document and e-mailed to me prior to testing date.

1. What are the two types of friction that affect the performance of your vehicle? 2. What problems related to friction did you encounter and how did you solve them? 3. What factors did you take into account to decide the number of wheels you chose in your design? 4. What kind of wheels did you use in each axle? What is the effect of using large or small wheels? 5. Explain how Newton's first, second and third laws apply to the performance of your vehicle. 6. Discuss the effect of the length of the lever arm in the pulling force of your vehicle. 7. How is the balance of a wheel, around its center, related to the vehicle’s performance? 8. How does the distribution of weight of the vehicle affect the traction of the wheels? 9. Discuss the major problems encountered in the performance of your vehicle and what did you do to solve them. NOTE: Your report is due prior to race day.

DUE DATES AND CHECKPOINTS There are 2 progress CHECK-POINTS.

CHECK-POINT 1: (4th week into your project) You must have completed your finalized design and gathered/purchased all component parts and materials for assembly. You must bring in all component car parts to school for approval.... be prepared to answer any construction questions presented to you (after examining your materials, I might ask questions that pertain to your car design... make sure you can explain what you are going to do with all the parts and construction materials and how your design works). Some car construction may have begun at this point.

CHECK-POINT 2: (6th week into your project) You must provide proof of construction progress on your project... you will bring to class either your partially finished car or your finished car for approval. Finished cars can be tested and modified if necessary for performance improvement. Modifications can be made as often as desired up to the day the project is due.

RACE DAY During your race, you must measure total distance travelled and time to travel this distance. A video recording of your car's journey must also be included. This can be done using your web camera or a video camera. We will be using Vernier software with this video, so remember to include a meterstick in your video.

MOUSE TRAP CARS

POST-RACE DAY We will spend one class period to determine the following . This will be used as your Unit assessment DATA and calculations to include for your Energy Unit assessment.  Distance traveled:  Average Velocity:  Averaged positive and negative accelerations  Potential Energy  Kinetic Energy  Mechanical Energy  Efficiency  Power Output  Inertia  Rotational inertia  Friction  Torque  Include a velocity/time and distance/time graph for this project

CAUTION: The car below is an example of a purchased car kit from a hobby store and is absolutely prohibited! There are several models available locally (example: Hobby Lobby) and from many sources on the web; they all are prohibited.

Note: the current national record for distance is 111 meters set in 1998. The current national record for speed is 5 meters in 1.2 seconds set in 1997.