10/10/2016 : Magnetic Potential Energy

Lab #13: Magnetic Potential Energy
Name:   Charles Xu,
Partner: Anthony, Michell
Date:     10/10/2016

Statement:
The purpose of this experiment is to verify that magnetic potential energy and kinetic energy are conserved.

Summary:
Unlike gravity potential energy or elastic potential energy, we have equation, we don't have an equation for magnetic potential energy. In order to accomplish this experiment, the first step we have to find an equation for magnetic potential energy. To do so, we first level the air track and measure the separation of the magnetic when the glider is at rest. Then, we raise the air track to multiple angles and collected different separation. As the air track goes steeper, the separation becomes smaller. We using the theory that magnetic force will equal to gravitational force component parallel to the track. Then, we use power fit to find the A and n for the function of F=Ar^n.

Force vs. r graph

From the curve fit we have our A value as 0.0004724, and n value as -2.004. Then we take the integral of the negative force function and we have our magnetic function. 

After we have the equation of the magnetic force, we place the air track back to horizontal. We give a little push to the glider so that it can go toward the magnet and pushed back by the magnetic force without contacting with the magnet. We measure data with motion sensor and plug in datas. Then we plot Magnetic Potential Energy vs. Time graph and Kinetic Energy vs. Time graph.

Magnetic Potential Energy vs. Time graph and Kinetic Energy vs. Time graph

From the graphs, we can see that when magnetic potential energy increases, kinetic energy decrease. As time goes by, the total energy remain almost the same. 

Also, we plot the Position vs. Velocity graph.

From this set of graphs, we could tell when the glider got to the point that pushed backward by the magnetic force. 

Conclusion:

As the datas and graphs shown, velocity decreases as the glider is getting closer to the magnet. The magnetic potential energy increases when the glider is getting closer to the magnet. Therefore, kinetic energy of the glider decreases when the glider is getting closer to the magnet. From the Magnetic Potential Energy vs. Time graph and Kinetic Energy vs. Time graph, we could tell magnetic energy and kinetic energy are conserved.