Joustrap Car Final Report

Kyle Macauley
Devon Buenrostro
Ricky Pearce
2.29.16
Mr. Yav
Period 5
Physics
TRAPDAT

Table of Contents:

Introduction
Design
Materials
Construction Procedure
Operation of Mousetrap Car
Results
Conclusion/Improvements

Introduction:

We were tasked with creating a car, powered by a mousetrap, with the purpose of battling another car while protecting an egg. We were provided with a ramp and an egg, everything else was up to us. Our initial ideas differed from the finished product. Our group wanted to use CDs for wheels because of their availability and size. After researching for a day, we decided to use other materials to create our car. Many of our initial ideas were scratched after we spent time discovering the best way to create a car.

Design:
We brainstormed about the general design of our car. Things such as how heavy we wanted it to be, the materials to use, and the reality of our ideas. Our main mistake came with how heavy we made the car. Our car was very heavy due to the material we made it out of. We used thick wood in hopes that our car would destroy rival cars in the jousting competition. Our car ended up being very long (the maximum length) and very heavy. This did not work well for us. We followed the initial design we had for the car but used different materials than what we originally planned. This was partially due to availability but also a change in plans. We failed to add much padding to our car because it was heavy and there was limited space. We decided to put our driver up high and build him a cart to sit in.

Materials:

Wood - $12
Duct Tape - Free ($5)
Skateboard Wheel - Free ($5)
2 RC Car Wheels - Free ($10)
Chopsticks - Free ($.50)
Mousetrap - $2
Fishing Line - $2
Pencil - Free ($.50)

Construction Procedure: 

1. Acquire all of the materials listed above. 

2. Use a thin wooden slab to create the belly of the car. 

3. Tape/glue two thin pieces of wood sticking out past the belly of the front of the car as well as the back. 

4. Drill holes in these four pieces, we will be putting the wheels between them. 

5. Tape the mouse trap to the middle of the wooden slab.
6. Attach a pencil to one side of the mousetrap.
7. Slide a chopstick between the drilled holes in the pieces of wood, on both sides.
8. Slide the wheels on. Make sure they are on tightly. Apply tape to ensure their tightness.
9. Attach a string to the pencil and wrap it around the back chopstick of the car.
10. The car should be ready to go and look similar to the picture.

Operation of Mousetrap Car:

The car is powered by a mousetrap. As the mousetrap goes from the open position to the closed position, it pulls on a string which is connected to the back wheels. This causes the wheels to spin and the car to move. The mousetrap has potential energy when it is cocked back. As the trap moves forward, the energy is conserved and transferred to kinetic energy. The work the mousetrap does on the car allows for it to move. The car must be heavy enough to have large enough friction to not spin out. Once moving, the momentum of the car carries it until gravity and friction stop it. The energy is always conserved, but it is transferred. We wanted our car to have a large amount of force so we made it heavy. This affected its acceleration but since F = Ma, the force was still relatively large.

Results:

Overall, our car finished tied for fifth in the jousting tournament. We did not preform as well as we would have liked to but it was a good effort. Our car preformed as well as it could have with the design it had. Our egg never broke which was an accomplishment. We lost in our second joust but made it to the semifinals of the losers bracket. Due to the weight of our car, it did not accelerate quickly. We have inserted pictures of our car in action at the jousting tournament.

Conclusion/Improvements: 

As we mentioned multiple times, our car was too heavy. We would make our car significantly lighter to increase its acceleration. With the lighter car, we would need more padding for our egg. A crumple system would help prevent a strong impact on the egg. We would use plastic instead of wood to make the car lighter. Wood was hard to use and especially hard to put together with only duct tape. Plastic would be easier to work with as well as providing the benefit of weight. Acceleration seemed to win the tournament because eggs were rarely launched out of cars. Crossing the middle line first would help win many more rounds rather than attempting to break the other car.