Alternative Energy Vehicle

Our Alternative Energy Car:

The Task

For this project, we were instructed to build a vehicle that would safely transport two passenger, (aka 250 gram rolls of 50 pennies) exactly five meters, or as close as possible to five meters. Hyundai engineers gave us this task, however, they did have restrictions for us. They told us, "Any type of potential energy is acceptable for the proposal except chemical and nuclear. All energy sources and Peripherals should be on board the vehicle. Remote Controlled vehicles are banned. Remember to account for friction. Your vehicle will travel on a smooth linoleum classroom floor with no modifications to the floor surface allowed."

Process Of Making Our Vehicle

• The first thing my group and I did was brainstorm as many ideas as we could for a way to accomplish the task within the criteria. After brainstorming, we figured out which ideas were practical for us to build. Then we went to the makers space and started blueprinting our best idea. The next few days we went to the makers space and started making our vehicle. We did some math to figure out the dimensions and measurements of the car. We ended up using a weight and pulley system to power our car. However, the static friction was too much for even the heaviest weight we could use to try and overcome it. So, we added a ramp at the begging, before the start line, to give your car the extra boost it needed to get going, and overcome the static friction. After adding the ramp, our car worked very well, and we were able to time the car going five meters. With our times we put our calculations on to a Google Spreadsheet, which we also used to graph our data. All of this information is in our google slides presentation shown above.

Explanations:

Spring Potential Energy is the energy stored in the stretch or compression of an object. The equation is PEspring=1/2kx^2. Our car did not use spring potential energy because we used a pulley instead, however, we did use it on our trebuchet.

Gravitational Potential Energy is the energy an object has due to gravity. On Earth, acceleration due to gravity is 9.8 m/s^2, which can be used in many different equations. You can calculate potential energy of a given object by using gravitational potential energy with the mass of an object and the height the object is at. PE=mgh. In our case, the entire car started with an amount of Joules of potential energy from being on the ramp, and number of Joules of potential energy from the weight on the pulley. Refer to the graph below.

Kinetic Energy is the energy of movement. Kinetic energy is found using the formula KE=(1/2)mv^2, where m is the mass of the object and v is the velocity of the object. Kinetic energy is measured in Joules, like every other form of energy. Our car quickly gained kinetic energy from rolling down the ramp, then it mostly remained constant, finally decreasing to zero as it came to a stop near five meters. Refer to the graph below.

Total Energy is the total amount of energy in a system. In our case, total energy was found using the potential energy at the very start, because, all of the energy held by our car was potential. We know that our potential energy is the same as the total energy because of a concept called conservation of energy. This principle states that energy is not created nor destroyed, merely transferred from one form to another. That means that the total energy in the system will stay the same the whole time. See the graph shown below.

Thermal Energy is the amount of energy that gets transferred to heat as the car is in motion. For this project, thermal energy was all the energy "lost" to anything other than kinetic or potential energy. In other words, any of the total energy that went into anything other than the movement of the car. This could be heat from friction, the sound the car makes, the sway of the weight as it goes down, ect. Thermal energy is found with; Total Energy- Potential Energy- Kinetic Energy. Thermal energy is also shown in the graph below.

Transfer of Energy explains how the car starts to move, and why it stops at the end. The graph below shows the total energy remains constant, and the potential energy decreases linearly after the ramp, as we expected. However, the kinetic and total energy lines are a little more interesting. There is a surprisingly low amount of kinetic energy throughout the system. However, when you look at the thermal energy line it is obvious why. The thermal energy increases steadily over time. As the car comes to a stop, the thermal energy is equal to the total energy. This graph is a visual representation showing how the potential energy is initially transferred to kinetic energy, then at the end, everything is transferred to thermal energy.

Rotational Inertia

Rotational inertia is the resistance of objects to changes their rotation. This means that the more mass toward the center of the ball gives it less inertia. The less rotational inertia an object has, the easier it is to get moving. The more rotational inertia the object has, the harder it is to get to move, but, it is also harder to stop. Our car as a mass, does not have rotational inertia. However, the wheels do. We gave the wheels less rotational inertia by putting a piece of wood int he center to hold the axle. This put the most mass in the center, giving the wheels less rotational inertia, making the wheels be able to spin faster, and stop smoother.

Reflection

This project, the two C's I think I did well were being a conscientious learner and having good collaboration skills. I think I was very cooperative, and productive during these past few weeks. I feel that I was more focused than usual, and I learned/ retained more information than I have in past projects. I think this was so because my group mates helped me by explaining things in depth so that I could fully understand. I think I was a good collaborator because I gave my group many good ideas to apply to our vehicle and solutions to problems that we had, while respecting their thoughts/ opinions. I think I really improved on listening to detail and instructions in this project. I also was very productive by getting things done that needed to be done. I think the things I did for my team helped us focus on making our car the best it could be.

The two C's that I believe I can improve on are character and communication. I think I should work on character in future projects and groups because it is very important to me to make everyone feel welcomed and free to share their ideas. I feel like everyone should feel comfortable being themselves and being confident enough to share their ideas, so in future groups, I want to work on my empathy and integrity to make sure that everyone feels comfortable. I also want to work on my communication skills, because sometimes I will worry too much about hurting someone's feelings, when they just need to hear my honest opinions. In the next project I will definitely work on these skills in order to make myself the best team mate possible.