Alternative Energy Vehicle
Table of Contents
Our Project
On November 12th we were given the task of making a vehicle, of any kind, that didn't use gas fuel, commonly used in today's cars. We had to find a way to precisely move our car as close as possible to 5 meters and safely transport two mock "people". These people have a combined mass of around 250 kilograms and will give our car more friction with the ground, therefore making it slower.
We decided on making a rubber band powered car to transport our people the 5 meters they need to travel. This car would be relatively easy to make, we know the physics behind a rubber band and it wouldn't require any kind of fuel, making it easy to run consecutively. Taking all this into account, we knew our final car design would run on spring power.
Our Presentation
The Video We Analyzed
IMG_6890.MOVAlternative Energy Vehicle Spreadsheet
Car Ramp Lab Spreadsheet
Reflection
This project I felt more in touch with what was happening in the group. I got to take a more prominent position in leading and generating ideas, I worked with my team to create a project I am proud of and fully understand. My teammates and I all cooperated to help make this project as successful as possible.
I maintained good work ethic and productivity and cooperated with my team to the best of my ability. I do, however, have room for improvement in empathy and leadership. Next project I will make sure to be as friendly as possible with my teammates and try to keep a good spot as a leader of the group.
Physics Concepts
Between this project and our last project we learned and reviewed on many things. We reviewed
Energy Types(Mostly Review):
Potential Energy/Kinetic Energy (J, Joules)
Potential energy is the energy something has at rest and kinetic energy is the energy something is using by moving. Work is equal to the change in potential and change in kinetic energy.
Gravitational Potential Energy (J, Joules)
Gravitational Potential Energy is the energy stored in an object giving it potential to move due to gravity, most likely earth's gravity (9.8m/s^2). Gravitational potential energy is quantified in Joules(J) and is the mass of the object times the gravity times the change in height, or height off the ground.
Spring Potential Energy (J, Joules)
The Spring Potential Energy is the stored Potential energy of a spring when it is stretched and is quantified in Joules(J). Spring Potential Energy is half the spring constant of the spring times X, the change in distance when stretched, squared.
Thermal Energy (J, Joules)
Thermal Energy is the energy of atoms and is the way energy can be "wasted" while energy is being transferred. Thermal Energy, like all forms of energy in physics, are quantified in (J) Joules. The more Thermal heat is being transferred, the less efficient the interaction is. If an object is moving it loses energy to heat, this is why machines and power-tools can overheat. Thermal Energy is Total Energy minus potential and kinetic energy because energy cannot be created or destroyed. Entropy, the lack of order and predictability, insures that all energy will eventually move to become heat energy.
Graphs:
A graph, if you didn't know, is a way of mathematically visualizing data. In physics you can compare data using a graph to show and conceptualize how the components interact. Moving along the y-axis, or the change in y, is vertical movement, and moving along the x-axis, or the change in x, is horizontal movement.
Slope (m)
Slope is the mathematical way of representing the relation between the change of the line along the y-axis (vertical "distance") and the x-axis (horizontal "distance"). Slope is represented with the variable "m" and can be calculated using the change in y, or the rise, divided my the change in x, or the run. When comparing physics components the slope of a line can represent the change in a different component.
When comparing components with time as the x-axis.
The slope of velocity = the acceleration
The slope of distance = the velocity
Area
Area under the section of a graph is the way of showing the average y value times the change in x.
When comparing components with time as the x-axis.
The area under the velocity = the distance
The area under the acceleration = the velocity
Example Graphs
Circular Motion and Rotational inertia:
Circular motion and rotational inertia define the basics of how objects rotate and revolve in a circular path.
Rotation (spin) vs Revolution (orbit)
Rotation (spin)
A rotation or a spin is when an object does not change position but spins around it's center of rotation. The Earth, for example, makes one rotation, also known as a day, in 24 hours.
Revolution (orbit)
A revolution, or orbit, is when an object moves in a circular path around another object or point in space. The Earth makes one revolution around the sun, in year, or 365.25 days
Tangential Speed (velocity, v, m/s) vs Rotational Speed (ω, rpm)
Tangential speed, also known as linear speed, is the movement of an object in a straight line towards a particular direction. Rotational speed is the speed that something rotates and is symbolized with the Greek letter ω. Rotational speed can be measured in rotations per second, degrees per second and mostly commonly RPM, rotations per minute.
If you are standing on a rotating object you are revolving around the center of rotation. The further you get from the center the faster you will be traveling because you will revolve in the same amount of time but you cover more distance. Your rotational speed is the same but you have more linear speed.
Centripetal Force vs. Centrifugal Force
Centripetal Force
Centripetal force is the force that pushes a revolving object inward towards the center of rotation (the center of the circular path).
Centrifugal Force (Fake force)
Centrifugal force is the feeling of being pushed outward while revolving in a circular path. Unlike centripetal force, centrifugal force is a fake force and is actually caused by inertia.
Torque (τ, Joules)
Torque is essentially work, W, in a circular path. Because of this; the formula for torque is the force times the distance to the center of mass, or the radius.
Angular Momentum (kgm/s)
Angular momentum is momentum(p=mv) in a circle. Angular momentum equals rotational inertia, I, times rotational velocity, ω. Rotational inertia goes up the farther the mass is away from the center of mass. This causes the rotational velocity to go down, so hollow objects are harder to rotate.
Friction
Friction is a force that effects two objects moving against each other. Friction amount is based on the variation of the texture of the materials. The more variation both materials have the higher a chance that the atoms will catch one another. Wood and rubber bands have a higher amount of friction because the atoms have more chances to collide. Metal and plastic are very smooth so they have less chance of collision.
Rubber bands
Wood
Plastic
Metal
