Car Physics

This year in science, we were paired up in groups to build a car powered only by a rubber band. There was a lot of physics and thought put behind the planning of our car. The rubber band moved the car by storing up elastic potential energy which then turned into kinetic energy when released. Newton’s Laws of Motion also come in handy when thinking about how to keep the car moving. “An object in motion stays in motion.” There was also a lot of thought put into the wheels. We had to be aware of the relation between the wheel diameter in relation to the distance the car will go. The bigger the wheels, the more distance the car will cover. Along with the wheel diameter, we had to think about the axle diameters in relation to the number of
rotations. The smaller the axle, the more times it will turn. Another thing is that the wheels and axle have to perform torque by spinning. If they don’t perform torque, our car won’t move at all. Drag the force of an object moving something like liquid or gas. We had to make sure that our car wasn’t affected by the drag of the car moving through the air. We used all of this information when building our car. We put a nail in the base of the car and another one in the dowel (axle). The rubber band went on the nail in the base then wrapped around the axle when twisted around the other nail.
While building our car we faced many difficult challenges.
Those challenges include making the car go ten meters, keeping the wheels straight, and figuring out how to power it. One requirement of our car was that it had to be powered by a rubber band using elastic potential energy. My group could not figure out how to attach our rubber band to the car. We thought about using a propeller but then realized that it wouldn’t take the car the ten meters. We then realized that if we winded it around the axle, the car would go farther. In the end, we attached the rubber band to two nails and wound in around the axle. Another problem was keeping the wheels straight so that the car wouldn’t turn. Our wheels were originally straight but after testing the car a bunch of times, the wheels became crooked. That made the car slower, and more wobbly. We had to unattach the wheels and glue them on straight again. My group also faced the problem of making it go the full ten meters. From the start, the car went about eight meters and then stopped. We came to the realization that we needed to take some weight off of the car. Too much weight makes it hard for the car to move in the first
place. To go along with the problems my group faced, I have some recommendations for anyone trying to tackle the task of making a rubber band powered car. First, have a plan. Building the car goes so much smoother when you have a basic plan to go off of. If you don’t you may change your mind halfway through or realize the car won’t work. Also, make sure your wheels have some friction. If the wheels are completely smooth the wheels could spin but the car would go nowhere. The wheels need to have some traction to the floor. Adding some friction to the wheels helps the car stick to the floor and go farther. Another tip is to watch the weight of your car. If you make it too light it will stop sooner because there is nothing to keep it going. On the other hand, if it is too heavy it will have trouble starting. The information of elastic potential energy and rubber band cars could be very important throughout life and to some people in their jobs.
A toy maker could use this information when making a toy that is elastic or is powered by some sort of rubber band. They would have to take the knowledge of the elastic potential energy and convert it into the planning of the toy. If not, the toy may not work correctly. Elastic potential energy is also found in a bow and arrow. Someone who makes, or uses bow and arrows would have to understand how they work in order to work with them. When the string is pulled back, the energy builds up. When released, it converts the elastic potential energy to kinetic energy to send the arrow flying
forward.