Coefficient of kinetic friction lab

[FS98]

Homework Statement

I need to find the coefficient of kinetic friction from a set a lab data that I found. I had a mass connected to a mass hanger by a pulley, and measured the acceleration of the mass with various amounts of mass on the hanger. In the attached image, the acceleration was measured multiple time as M2 was varied and everything else was kept constant.

Homework Equations

F = ma

Ff = uFn

The Attempt at a Solution

[/B]
I believe the force on M1 should be T - uM1g and the force on M2 should be M2g - T.

I'm not sure where to go from here. I would be able to solve for u given a single value of a and M2, but I'm not sure how I could solve using the entire set of data. Could I maybe use the average values for M2 and a because the relationship in linear? Or do I have to make a graph of some sort and use the slope to find the value for u from the entire set of data?

 

[BvU]

'm not sure where to go from here

You measure the acceleration a but your relationship only has a T. What is the link from T to a ?

 

[FS98]

You measure the acceleration a but your relationship only has a T. What is the link from T to a ?

I believe the a would come from the fact that F = ma. Replace F with M1a on one side and with M2a on the other. I think we can also get rid of T by substitution.

 

[haruspex]

I would be able to solve for u given a single value of a and M2, but I'm not sure how I could solve using the entire set of data.

You could find a value for μ from each test, then take the average. Or better, if you plot the calculated μ against M2 you might not get a horizontal line. Some kind of systematic error could result in a sloping or curving line. Then you would try to figure out what the source of error was likely to be and could make an adjustment.