Mrs. Singh's Physics Class Page
Jodie Leeka and Jon Wiegand Physics Honors Mousetrap Car Project November19, 2002
Mousetrap Car
Partner: Jon Wiegand and Jodie Leeka
Purpose
Make a vehicle powered by a mousetrap.
Materials
Mousetrap, 2 CDs, Fishing line, Super Glue, Elmer’s Glue, Hot Glue & Hot Glue Gun, Ribbon Spool, Dowel Rods, Balsa Wood, 8 Plastic wheel bearings (4 small, 4 large), Ribbon, Masking Tape, Razor Blade, Coping Saw, 2 Balloons
Procedure
>Assembling the Car
Cut two 12-inch pieces of square dowel rods and a sheet of balsa wood eight inches long with the coping saw. Use super glue to connect the runners to the body of the car, with more of the runner past the front side of the body.
Next, cut two round dowel rods six inches long to be the axels. Slip on two of the large wheel bearings onto one axel; glue a small plastic wheel bearing to the axel on each side, and a CD to each of those using a hot glue gun. Then, glue the large wheel bearings to the runners extended from the body of the car. Cut the two balloons to make a loop to stretch around the CDs. These are the back wheels. Wrap a wide ribbon around the axel and use masking tape to hold it in place. This serves as a larger area for the fishing line to wrap around, increasing the torque.
For the front wheels, align a small wheel bearing, the ribbon spool, and another small wheel bearing on the axel. Glue all of these materials together similar to the back wheels. Slip a large wheel bearing onto the axel on each side, and glue them to the runners extended towards the font of the car.
On the mousetrap, cut the wire to leave only a short lever arm to move. Attach the dowel rod as an extension to the lever arm and attach the fishing line to the end of the dowel rod. Hot glue the other end to the ribbon on the back axel. Glue the mousetrap to the wooden body of the car.
>Working the Car
To make the car move using the mousetrap, wind the fishing line as far as it will go around the ribbon on the back axel. Set the car on the ground and let go.
Analysis
1. How did you get the idea for this project?
http://www.docfizzix.com/how_work.htm
Our dads
Mouse Trap Cars
2. To plan for this project, both of us contributed. We planned first, and then went to the store to purchase the materials we didn’t have in our houses.
3. For our body, we used two square dowel rods glued to a sheet of balsa wood. We considered the aerodynamics of the car a little, and made it low to the ground and slightly angled down in the front. We also made sure the car had minimal air resistance. To minimize friction, we used plastic pieces as wheel bearings as well as putting a little bit of graphite dust where they met. This caused the axels to move very freely with no hesitations.
4. In the beginning, we made one model of a car that didn’t move. The body of the car was very fragile, so we decided to start over. When we completed the final car, we tested it and made some minor changes to improve its motion. We looked back at the same sources of reference for the second car.
5. I learned a lot from this project. I think you should give it to future students, but I can’t think of any ways to change it.
6. I think my partner and I worked about the same amount on this project. We both contributed greatly. I think the time given was sufficient.
Conclusion
In this lab, I learned a lot more about applying physics to constructing a vehicle to perform the best it can. Things we had to keep in mind were friction when the car first started moving, momentum throughout the travel time to increase distance, and torque getting the car started. It took a lot of trial and error, testing different models and ideas for the design and mechanics of the car. We made a totally different car for the final product because our first model wouldn’t move. We figured this was because of several different reasons, mainly because the torque was so small, the back wheels (old records) were extremely heavy, and the mousetrap couldn’t produce enough force to make it move. When we made the car over again, differently, we kept these factors in mind and used our experience of the first model to help us design the second.
Mouse Trap Car Measurements
Length of Car = 38.5 cm
Length of Lever Arm = 17.6 cm
Length of Fishing Line = 32.5 cm
Wheel Diameter/Axel Diameter Ratio = 11.5cm/.6cm
Longest Distance Traveled = 17.3 meters
