For our hybrid car we created a car powered by rubber bands. It was made by Joaquin Arellanes, Josh Franks, Hunter Gray and myself. It consisted of materials such as cd's, pvc pipe, wood, screws, nails, a small cup and rubber bands. It was primarily wood held together with hot glue and zip ties. It was approximately 20 inches by 10 inches. The wheels of the car were made out of cd's and the axel of the wheels was a wooden rod. The base of the car was made of two wood planks. The pieces holding the axel were made out of pvc pipe and were held onto the wooden planks with zip ties. The cup's purpose was to hold the 250 gram weight in place so it wouldn't slide around the car. It took 2 hours to create and an hour to perfect the hybrid car. The driving mechanism was very basic. It started by winding up the rubber band around the axel which when you let it go, powered the car. Based on the amount of times the rubber band was wound up would determine how far the car went. Our goal was to make the car go 5 meters while holding a 250 gram weight. Our car often went around 4.5 meters to 5 meters consistently. The main concept in this project was energy transfer. Our car was able to run because of the energy transfered throughout the car. For example, the potential energy came from when the rubber band was wound around the axel. When the axel was unwound, the energy was converted to kinetic energy in the process. All the potential energy that is not converted to kinetic energy is then converted into thermal energy and lost as heat. Specifically our car started with 7 joules of potential energy. Just before the halfway mark, our car 1.53 joules of potential energy and 0.26 joules of kinetic energy. This means that 5.73 joules were lost to heat. At the end of the car’s journey, all energy was lost to heat. Along with the actual car, we created a presentation that showed our data and calculations about the car. We had to present our project and protoype in front of the class. The presentation relates to Math in the sense that we had to calculate components of our car. Concepts -Potential Energy - the energy possessed by a body by its position relative to others, stresses within itself, electric charge, and other factors -Kinetic Energy - energy that a body possesses by virtue of being in motion -Thermal Energy - the energy that comes from heat. This heat is generated by the movement of tiny particles within an object. -The faster these particles move, the more heat is generated -Momentum - the quantity of motion of a moving body, measured as a product of its mass and velocity -Acceleration - increase in the rate or speed of something
From our first design to our final design, one component we changed was the length of the base of the car. We found with the first design the length of the car was too short, causing it to not fullfill it's maximum distance. The first design only went approximately 3 meters each time we tested it. Making it longer allowed for a longer rubber band, and thus making the car travel further. Another component we changed was taking off the rubber bands off the wheels. The traction helped but the friction on the ground slowed down the car too much. By taking off the rubber bands, there weren't any bumps in the wheels causing less friction and a smoother, faster ride. Our group worked together well because we had effective communication and a willingness to keep an open mind. Everyone accepted each other's suggestions. Another aspect that worked well for us was the overall idea of our car. The rubber band around the axel worked well and we only needed a few small adjustments to make it function. One of the two things I learned about myself was that I am able to commincate well in a chosen group setting. I felt comfortable in expressing my opinions and ideas. Another thing I learned about myself was that I can be open to listening to other's ideas. Sometimes when you have an idea in your mind about how a project might work best, it never hurts to listen and try others differnt ideas and thoughts. With these projects always comes peaks and pits. One of the pits of this project was time management. We found ourselves preparing the presentation with not a lot of time and that was a downfall. Another pit was that we sometimes stuggled with distribution of our roles. A good idea for next time would be to establish our roles and repsonsibilities at the beginning of the project. One peak about the project was communication. We communicated really well and heard everyone's ideas. Another peak was the overall idea of our car. The rubber band around the axel worked well and we only needed a few small adjustments to make it function. We didnt make many changes just small thiings such as the length of the car. This project made me learn a lot about about all kinds of energy. Also, I learned how beneficial it can be to have a thorough original plan. I enjoyed working on this project becasue it dealt with a problem that exists in today's world (finding an alternative to a gas powered car). It was interesting to see all the different (and similar) ideas that my classmates came up with. Maybe one day we will be driving around in rubber band powered cars.