Lab #12 Magnetic Potential Energy

Purpose: Since there is no definite formula for magnetic potential energy like kinetic and elastic have, we will be deriving a formula through an experiment that has us recording the force of a magnetic at different scenarios.

This experiment is based on an air track. There is a glider on the track that has a magnet attached to it. Then there is another magnet attached to the track. The other magnet is repulsed by the one on the glider that way they will always be at a certain distance.

For the first part of the lab we had to raise one end of the track in order to measure how close the glider will get to the magnet at certain angles. We continued to raise the track until the distance no longer moves any closer. In the end we measured 6 different times.












The diagram above shows everything that is being measured. However, instead of measuring the height we recorded the angle of the rise.

Below are the six recorded angles and measurements being used. After these were recorded we plugged them into logger pro and used a power fit. We had to change the angles into radians and find the force (mgsin(theta)) of each of the 6 measurements.

In the end we had to scratch out the last point of our data because when put in with the best fit line the point was pretty far from the curve and the rest of the data.

With the A and B we were able to derive a formula for the magnetic potential energy.

After the formula was derived we are able to continue on to the second part of the experiment. This part was generally the same as the beginning but it instead of angling the track up it is going to be left parallel to the table top. Then we push it gently so that it collides with other magnet and wait for it to stop. During this whole process a motion detector that is connected to logger pro is running and recording the movement of the glider. The motion that the detector is recording is the separation in the calculated columns below.

Once collected we had to create separate calculated columns for separation, kinetic energy, magnetic potential energy (use formula derived) and total energy.

Then we would graph kinetic energy, magnetic potential energy and total energy vs time in order to see that the energies are conserved.

Having the graph stretched out and expanded like it is it is hard to imagine that it is conserved. Generally when a graph is conserved it is a straight line but if we were to expand the graph more it is easier to see.