Potential+and+Kinetic+Energy+Lab


 * Title:** Potential and Kinetic Energy Lab


 * Primary Author:** Peter


 * Contributing Author:** Jake


 * Abstract:** The goal of this lab was to determine the relationships between potential energy(PE), kinetic energy(KE), and total mechanical energy(TME = PE + KE). In order to determine the relationships we pushed a cart up a ramp and graphed the three energies during that time. Our results showed us that kinetic energy and potential energy are inversely related, and that total mechanical energy remains constant throughout.


 * Introduction:** In this lab we will be using a car and a ramp. The ramp will be angles. Starting at the bottom of the ramp, the car will be pushed up the ramp and then fall back to its original position. The graphing program will be used to measure the amount of potential and kenetic energy in the car throughout the experiment. We connected potential energy to the lab by examining the height. We know that the height of the car will increase as it goes up and decrease as it falls back. We also know that potential energy increases with height. So we know that potential energy should increase when the car is pushed upward. Kinetic energy is connected to the speed of the car. As the car climbs up the speed would slow down and the opposite will happen as it falls back. The theory behind all this is that both potential and kinetic energy should add up to the Total mechanical energy. The graph will help us understand that and the seeing the experiment will help us understand energy and the theory behind it more.


 * Method:** A cart, ramp, and motion probe were used during this lab. The computer program called LoggerPro was used to record data and produce PE, KE, and TME graphs. The probe was to be placed at the top of the ramp so that an accurate reading could've be taken. Before the cart was pushed, it was important to mark the position at the bottom of the ramp as "0" on LoggerPro. The cart was pushed up a ramp of approximately 18 degrees. The cart was supposed to be pushed in a way that moved more than halfway up the ramp, and provided a smooth graph without any jumps.

The top graph represents the potential energy over the time that the cart was pushed up the ramp, and came down. The middle graph represents the kinetic energy for the same time interval. The bottom graph represents the total mechanical energy, also for the same time interval. The potential energy graph has a parabolic shape. This is because as it is going up the ramp, the potential energy, or position energy, is increasing and as it goes down the ramp this value decreases. This is clearly shown in the graph and the highest point that the cart reaches is also very clear. The kinetic energy graph is the opposite, or inverse, of the potential energy graph. At the beginning of the push the cart had a very high velocity, causing the kinetic energy value to be high. As the cart reached the peak its path, it slowed down until it stopped. This is also visible as the lowest point in the graph, because the cart has no velocity. The cart then gains speed going down the ramp and the kinetic energy goes back up to where it was at the beginning, until the cart is stopped completely. The total mechanical energy graph is different than the other two. As the cart is being pushed the TME graph shows an increase, as do the other two graphs. During the time that the cart was not being touched the graph remains constant.
 * Results:** The following are PE, KE, and TME graphs of the experiment:

The vertical lines are visible on the graphs. The amount of work performed during this process was about positive(+) 0.7 joules.
 * Analysis Questions:**
 * 1. Draw vertical lines through the section of time when you were pushing the cart with your hands. How much work did you perform in this process?**

As the graphs show, when the potential energy was increasing, the kinetic energy was decreasing. This happened because at the time when PE increases the cart is losing velocity, therefore the kinetic energy is decreasing.
 * 2. Make a general statement about what was happening to the kinetic energy as the potential energy was increasing.**

The kinetic energy increased at two different places on the graph, and at both places the potential energy was doing something different. The first time KE increases is when the cart is being pushed; during this time PE is also increasing because the cart is going up the ramp. The second time KE increases is when the cart is gaining speed as it goes down the ramp; during this time the PE is decreasing because the cart is going down the ramp, and therefore losing position.
 * 3. Make a general statement about what was happening to the potential energy as the kinetic energy was increasing.**

Note the "x" on the graph. The kinetic energy is 0 when the potential energy is at its highest point. This makes sense because at an objects peak its velocity is 0 and this is proven by the graph.
 * 4. Place an "x" on the potential energy graph when the cart is at its highest position. What was the kinetic energy when the cart was at this position? Does this make sense?**

The amount of work performed on the cart in order to stop it was negative(-) 0.7 joules, the opposite amount of work that it took to push the cart.
 * 5. How much work did you perform on the cart in the process of stopping it?**

The total mechanical energy graph shows that the TME needed to push and stop the cart are the same as the KE values. The part of the graph where the cart isn't being pushed or touched remains constant at a value of about 0.7 joules.
 * 6. Make a detailed explanation about the information the TME graph displays.**


 * Conclusion:** In conclusion there were many things learned from this lab. The graphs helped to show the relationships between PE, KE, and TME. It is evident that potential energy, or PE, is effected by the position of the object. The kinetic energy, or KE, is effected by the speed or velocity that the object has. The total mechanical energy, or TME is a constant value when there is no horizontal force on the object.