Hybrid Car Project
This project began with the STEM Marin class receiving a letter from Hyundai asking us to create a energy efficient car with out using gasoline or any chemical energy. Our car that we create must be able to carry 250g and stop right at 5 meters.
Reflection
My group started our research right away. We found a pretty simple way to power our car, which was to use balloon power. The balloon powered car worked great until we put the 250g onto it. We quickly realized that the balloon powered car wouldn't be able to carry the weight. We then continued with some more research. We saw that the rat trap car seemed to work really well. We began to build and almost instantly found problems with the string that we were using. We experimented with using fishing wire instead of string, which worked a lot better. Even though some times the rat trap car would come close to the 5 meter finish line, it wasn't very consistent. Our next and final car that we created is the "Speedy Mobile" and it is powered by rubber bands. The Speedy Mobile was by far the fastest, lightest, and most efficient car that we created. It was not only able to carry 250g, but it was able to carry over 1,000g and was still able to reach the 5m mark with out a problem. I thought that my group worked very well together. If I had to change on thing about this project, it would change the amount of time that we spent trying to get the balloon powered car to work. I would also have focused more on the rubber band idea from the beginning of the project. This was a fun project because even though there was building involved, there was also some computer use incorporated into the project to created the presentation and graphs.
FInal Product
COncepts:
Friction~ Force in opposition to motion. We put rubber bands on our wheels (the CD's) to create grip. (friction)
Pressure~ amount of force per unit of area. You can calculate pressure by dividing force by area.
Energy~ the ability to do work. Work is equal to the change in kinetic energy which is equal to the change in potential energy. Our car was able to hold over 1000g.
Kinetic Energy~ energy due to movement/motion. Kinetic Energy equals 1/2(mass)(velocity)^2 We made sure that our car was very light so that it would have lots of kinetic energy.
Gravitational Potential Energy~ energy due to gravitational pull and height. The equation would be: mgh=PEg
Spring Constant~ the measure of elasticity/firmness of spring. The equation would be: F=kx or mag=kx. We counted how many times our rubber band wrapped around the axis, and counted how many times it unraveled at every meter. Thats how we found the spring constant.
(Spring) Elastic Potential Energy~energy due to the compression or expansion of elastic material. Equation: PEg=1/2kx^2. For our spring constant we used a rubber band. We measure the elastic potential energy by using a spring to see how many newtons of force our rubber bands exert.
Power~ rate at which work is done. Our car was very powerful, because it was light and fast.
Thermal Energy~is the energy lost in the transfer of potential energy to kinetic energy.
Pressure~ amount of force per unit of area. You can calculate pressure by dividing force by area.
Energy~ the ability to do work. Work is equal to the change in kinetic energy which is equal to the change in potential energy. Our car was able to hold over 1000g.
Kinetic Energy~ energy due to movement/motion. Kinetic Energy equals 1/2(mass)(velocity)^2 We made sure that our car was very light so that it would have lots of kinetic energy.
Gravitational Potential Energy~ energy due to gravitational pull and height. The equation would be: mgh=PEg
Spring Constant~ the measure of elasticity/firmness of spring. The equation would be: F=kx or mag=kx. We counted how many times our rubber band wrapped around the axis, and counted how many times it unraveled at every meter. Thats how we found the spring constant.
(Spring) Elastic Potential Energy~energy due to the compression or expansion of elastic material. Equation: PEg=1/2kx^2. For our spring constant we used a rubber band. We measure the elastic potential energy by using a spring to see how many newtons of force our rubber bands exert.
Power~ rate at which work is done. Our car was very powerful, because it was light and fast.
Thermal Energy~is the energy lost in the transfer of potential energy to kinetic energy.