Energy Efficiency on Level Track

 Analysis:

Formula to find energy efficiency:

Trials:

The initial velocity of the cart does effect the energy dissipation. This can be seen from the data obtained from the experiment. It is also important to note that the ratio of velocities will never be 1, because the magnetic bumpers are not 100% efficient. We also lose of the energy in the form of friction. Friction does a small amount of negative work on the system. 

Conclusion:

The energy is dependent on the initial velocity of the cart, but we can estimate that the energy efficiency of the magnetic bumpers is roughly 60%. Therefore, we are losing 40% of the initial kinetic energy of the system due to the magnetic bumpers and work done by friction. When compared to our partners group using the inclined track, we can see that their bumpers are even less efficient than ours. They proposed that their work done by friction was greater in comparison; leading to more energy loss. 

Lab: Analysis of the Coefficient of Friction

 Analysis:

Formulas:

1. Using the formulas for frictional force and normal force, we arrived at these results when varying the mass:

2. Graphing frictional force vs. normal force:

3. Using the formulas for frictional force and normal force, we arrived at these results when varying the height (angle):

4. Graph of frictional force vs. normal force:

5. Respective Uncertainties:

The two graphs seem to be quite different. Although both linear, their slopes and y-intercepts are not similar.

Conclusion:

The coefficient of kinetic friction for wood on aluminum, calculated by the slopes of the graphs, was found to be 0.7. This does not match with our prediction (within uncertainty) being 0.2.