During the hybrid car project, we had to design and build a clean energy car that ran without using gas or batteries. We had two days to design and blueprint, 3 days to build the car, and 3 days to work on our presentation. Our car was powered using a mousetrap. We connected a string to the trap and to the front axle of the car. After we loaded the mousetrap, it would pull downwards. The string would also be pulled, which would cause the axle to rotate and the car to move. During this project, I had the same group that I had during the Fire Away project: Daniel and Kaleb.
Physics Principles and Equations
During this project we used many physics concepts and equations. Below, all of the physics of this project are explained.
Distance vs Time- This means the distance the object traveled, compared to how long it took for it to get there. In our project we used a graph to show this. On the graph, the velocity of the car would be the slope of the line, because velocity is d/t.
Distance vs Time- This means the distance the object traveled, compared to how long it took for it to get there. In our project we used a graph to show this. On the graph, the velocity of the car would be the slope of the line, because velocity is d/t.
Velocity- The rate that an object travels in a certain direction. Velocity can be found by using the equation v=d/t. Our car had an average velocity of .3 m/s.
PE Spring- Also known as spring potential energy. The energy stored by stretching or compressing an elastic object. Our car used PE spring in the mouse trap. The coiled wire in the mouse trap was stretched, then snapped back together because of its spring potential energy.You can calculate this by using the equation PEspring=1/2kx^2. Our car had a PE spring of 2.62J.
PE grav- Also known as gravitational potential energy. It's the energy an object has due to its position at a height or in a gravitational field. PE grav is represented by the variable PEg, and the equation to find it is PEg=mgh. We did not use PEg in our project.
KE- Stands for kinetic energy. This is energy due to motion. You can find it by doing KE=1/2mv^2. Our average KE was .0135J.
TE- Also known as thermal energy, this is energy converted to heat. By the time our car had stopped we had 0.787J or TE.
Conservation of Energy- When objects move not all of their energy is converted from PE to KE. Some energy is lost to friction. However, energy can never be created or destroyed, so the energy has to be going somewhere else. This lost energy is turned into heat (thermal energy) and sound. In order to maximize your the amount of PE that is transferred into KE, you have to minimize the amount of energy lost to sound/heat. The best way to do this is to reduce the friction.
Friction- Force opposing the direction of motion due to roughness at the molecular level. In this project we needed more friction in some places, but less friction in others. We needed friction between the wheels of the car and the ground, otherwise the wheels would just spin in place and the car wouldn't go very far. However, we needed less friction between the wheels and the axles. Too much friction in this area would cause the axles to spin slower.
PE Spring- Also known as spring potential energy. The energy stored by stretching or compressing an elastic object. Our car used PE spring in the mouse trap. The coiled wire in the mouse trap was stretched, then snapped back together because of its spring potential energy.You can calculate this by using the equation PEspring=1/2kx^2. Our car had a PE spring of 2.62J.
PE grav- Also known as gravitational potential energy. It's the energy an object has due to its position at a height or in a gravitational field. PE grav is represented by the variable PEg, and the equation to find it is PEg=mgh. We did not use PEg in our project.
KE- Stands for kinetic energy. This is energy due to motion. You can find it by doing KE=1/2mv^2. Our average KE was .0135J.
TE- Also known as thermal energy, this is energy converted to heat. By the time our car had stopped we had 0.787J or TE.
Conservation of Energy- When objects move not all of their energy is converted from PE to KE. Some energy is lost to friction. However, energy can never be created or destroyed, so the energy has to be going somewhere else. This lost energy is turned into heat (thermal energy) and sound. In order to maximize your the amount of PE that is transferred into KE, you have to minimize the amount of energy lost to sound/heat. The best way to do this is to reduce the friction.
Friction- Force opposing the direction of motion due to roughness at the molecular level. In this project we needed more friction in some places, but less friction in others. We needed friction between the wheels of the car and the ground, otherwise the wheels would just spin in place and the car wouldn't go very far. However, we needed less friction between the wheels and the axles. Too much friction in this area would cause the axles to spin slower.
Our Presentation
For the Hybrid Car project, we had to create a presentation about our car. My group decided to do a slideshow. It includes a video of the car, graphs displaying data about the car, and our main selling points.
Reflection
The most difficult part of this project was definitely the time management. My group's first idea for our car didn't work, so we had to try to come up with a different idea. Changing our car meant that we lost almost half of our build days. We were very behind, so when the build days were over and the presentation days had started, we weren't done. The first day for working on our presentation we still had to work on the car. We should have planned everything out better, and in much greater detail. My group would also get easily frustrated with each other. I need to work on staying calm and discussing things reasonably with my other group members. Remaining under control will make it easier to tell others what I'm thinking, and lower the tension level between others. Although our car didn't work, I think we had a good idea. With more time it would have been possible to improve the performance of our design. The main problem was axle stability, which we could easily fix with two correctly placed PVC pipes. I learned a lot during this project, one of those things being how to make a graph on google sheets. I also learned about the 3 by 5 rule, which I can use to improve future slideshows that I make.