Magnetic Potential Energy Lab

Ana,  Jonathan, and Andrew

4/17/17

For this experiment we are trying to show that the energy is conserved when the cart moves from one end of the cart to the other. In order to do this we will get our kinetic energy and our magnetic potential energy and show that they are constant at every location. In order to do this we will first have to do some experiments that will allow us to find our potential energy.

To start off this experiment we first have to set up a track with a frictionless cart with a magnet on one end, and a magnet attached to one end of the track. We then leveled the track and checked to see what the repulsion distance is between the two magnets. Then we lifted the track to a certain angle and then once again measured the distance of the repulsion. We repeated this again four more times each time doing it at a different height. The magnetic repulsion force between the two magnets will be equal to the gravitational force component parallel to the track. We then plotted a force vs repulsion distance graph and used this to get values for our equation F=Ar^n.Then we used this equation to get our potential energy by integrating it. This gave us the equation for the potential energy. Once we were done with this we verified the conservation of energy by using a motion detector to measure both the speed of the cart and the separation distance between the two magnets. Then using the data that the motion detector gave us we were able to get graphs for the Kinetic Energy and the Potential Energy.

How we calculated our F value

The Magnetic Force

The equation for the Potential Energy of the magnet

Our expectation for the graph of the kinetic energy magnetic potential energy and the total energy was that we would get a nice straight line for the total energy (dark green) and the inverse of the red line for the kinetic energy however this wasn't the case. The line for our kinetic energy decreased as the time went on this is due to our cart slowing down. This means that our track wasn't as frictionless as we thought it was. Most of the errors in our graphs have to do with our track not being frictionless. The equation for our potential energy did a good job of giving us the graph that we were looking for. 

Overall we were able to get an equation for the our potential energy but we were not able to prove that the total energy is conserved because our graphs were not able to show this. The line for our total energy should have been a straight line that was equal to the initial kinetic energy of our cart.