6. Cut the wooden dowel so you have two pieces that are both about two inches longer than the width of the chassis you have made. These will serve as your axles that rotate the wheels. Stick the dowels through the eye loops. Make sure that the axles are straight and that there is room for them to spin in the eye hooks.
7. Cut holes a little bit smaller than the dowel through the center of each wheel, then attach the wheels to the base. Put the large wheels on the back of the car, opposite the snapper arm. Wrap a small rubber band around the axle on either side of each wheel so the wheels can’ t fall off.
8. Tie a string very tightly to the snapper arm on the mouse trap. The string should be long enough to just reach to the back axle.
9. You may need someone to help you with this last step. Carefully pull back the snapper arm until it reaches the other end of the trap. Hold it in place while your helper wraps the string tightly around one side of the axle. Holding the string tightly, set the car on the ground and carefully let go of the trap- the string should be wound tight enough that it holds the trap in place. Next, make sure everyone’ s hands are out of the way and then let go of the string. The trap will snap forward, propelling your car.
RESULT:
A set mousetrap is full of potential energy which, when released, is converted to kinetic( motion) energy. The design of your car allowed that energy to be transferred to the axle to make the wheels turn. When the trap snapped closed, it yanked the string forward. As the string was pulled, friction between it and the axle caused the axle to rotate, spinning the wheels and moving the car forward.
SCIENCE PROJECT
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SAFETY NOTE Mousetraps are dangerous! If one snaps back on your hand it could break a finger. This project requires adult permission and supervision.
If you want to have the fastest car, here’ s what you need to know and to do.
• Thicker axles increase speed.
• Try using different sized wheels in front or in back.
• Adjusting the length of the body and string alters the speed of the mousetrap car.
• Make it more durable by using lightweight wood such as balsa or basswood instead of cardboard.
• Use CDs or records as the wheels.
WINSPIRE: Empowering youth | February, 2017