# Force and Lever Arm

Topics: Force, Classical mechanics, Mass Pages: 2 (749 words) Published: March 16, 2013
1. What are the two types of friction that affect the performance of your vehicle? The first type of friction that affects the mousetrap car is called rolling friction. This type of friction occurs in between the wheels of the car and the surface of the ground it moves on. The second type is called the sliding friction which occurs in between the axles and the brackets.

2. What problems related to friction did you encounter and how did you solve them? We noticed that at times the car would come to a sudden stop. We realised that is most likely caused by too much rolling friction between the axle and the frame, thus causing the wheels to stop turning which in turn makes the car stop. We solved this by disassembling the axle from the frame and re-attaching it to larger axle holes in order to make sure that they won't press against the frame as they spin.

3. What factors did you take into account to decide the number of wheels you chose in your design? The more wheels present in your vehicle, the more friction will be present. More friction present means more rolling mass. The more rolling mass you have, the greater the needed energy to travel farther and faster is. This means then that you must only use as many wheels as needed to keep the vehicle stable.

4. What kind of wheels did you use on each axle? What is the effect of using large or small wheels? For this project, we used water bottle caps wrapped in electrical tape. The size of the wheel in comparison to the axle it is placed on greatly affects the torque (or the pulling force) as well as the pulling distance. If you larger wheels and a smaller axle, you will achieve greater distance but less power. Therefore, you must find a balanced ratio between the size of the wheel and the axle because if it has too little power, it will not end up not moving at all.

5. Explain how Newton's first, second, and third laws apply to the performance of your vehicle. Newton's first law states that the vehicle...