Purpose:
The goal of this lab is to verify that conservation of energy applies to the system of the cart with the fixed magnets. We will be using an air track with a glider on top of it with strong magnets attached to the end of the glider and the wall.
Procedure:
1) Our first step is to recognize that this is magnetic potential energy, not the usual gravitational potential energy or elastic potential energy. This means we must find an equation for the magnetic potential energy. The relationship that we will obtain the magnetic potential energy is the integral of the force with respect to r, integrated from infinity to r. r is the distance between the glider and the magnetic attached to the wall.
2) Next we will level the air track so that it creates a height h that will allow the magnetic repulsion force to be equal to the gravitational potential energy of the cart that is parallel to the air track. By tilting the air track we will have created an angle theta which we must calculate. We must tilt it at different angles so we can plot relationship between magnetic force and the separation distance.
3) We then plot a F vs r graph. The graph will be assumed to be a power law F=Ar^n. In order to get the values of A and n we must apply a curve fit to the graph.
4) To verify conservation of energy, we attach an aluminum reflector to the top of the air track. We place the track near the magnet. We then run the motion detector and see the relationship of the distance the detector reads and the separation distance between the cart and magnet. We can now measure the speed and separation between magnets at same time.
5) We can calculate the graphs of potential, kinetic and total energy of the system now by placing the track at the opposite end of magnetic, give it a gentle push and use logger pro to calculate the graphs.
Conclusion:
We have found how to calculate magnetic potential energy even though it was not straightforward as other types of potential energy. Energy was conserved at the end as expected and found the force function from the graphs we plotted and saw the relations between kinetic and potential energy from the experiment.