Coefficient of Friction Lab

 For each new block mass and video, calculate the magnitude of the kinetic frictional force from the acceleration.  Also, determine the normal force on the block. For each angle and video, calculate the magnitude of the kinetic frictional force from the acceleration.  Also, determine the normal force on the block.

Data:

Eq. used:

Graph the magnitude of the kinetic frictional force against the magnitude of the normal force, for a constant angle of incline.  On the same graph, show your predicted relationship.

Predicted Coefficient Value: 0.20- 0.60

Graph the magnitude of the kinetic frictional force against the magnitude of the normal force for a constant block mass.  On the same graph, show your predicted relationship.

Predicted Coefficient Value: 0.20- 0.60

Calculate the uncertainty in your experimental technique.   Do your two graphs agree?

The uncertainty is 0.116. The value for constant angle of incline (0.379) DOES agree within uncertainty, but the constant block mass (0.792) value does NOT agree within uncertainty.

Conclusion: 

What is the coefficient of kinetic friction for wood on aluminum?  How does this compare to your prediction based on the table?

The calculated coefficient of kinetic friction is 0.379. This value falls within our prediction that we found on Google which was between 0.20 and 0.60.

What are the limitations on the accuracy of your measurements and analysis?  Over what range of values does the measured graph match the predicted graph best?  Where do the two curves start to diverge from one another?  What does this tell you?

The limitations are mostly human error when it comes to measuring the time at which the block slides, the measured height of the system, and how the weights were arranged on the block. The range of values that matched the prediction was the data from the changing block mass. The curves diverge as mass increases due to more difficulty in calculating the time it takes the block to get to the bottom.