# Work done by friction on an incline plane

1. Dec 5, 2008

### GoSS190

A block of mass M is being pulled up an inclined plane at a constant speed, by an attached rope that exerts a tension T. The block is pulled a distance L. The plane makes an angle θ with the horizontal, and the coefficient of kinetic friction between the block and the incline is μk.
a.) What is the work done by the rope?

b.) Find the total work done on the block, Wtot = Wcons + Wnoncons. Verify that Wtot = ΔKE.

Suppose that the rope is attached to the downward side of the block, and it is pulled down the plane, a distance L. The tension in the rope again has magnitude T. Assume once again that the sled is pulled at a constant speed.
a.) What is the work done by the rope?

b.)Verify that Wnon-cons = ΔPE + ΔKE by first calculating the change in kinetic energy.

I know work is equal to Force times the distance the object moved and that frictional force is equal to mgcos(theta)

2. Dec 5, 2008

### LowlyPion

Start by drawing a force diagram.

What forces is the rope working against? Over what distance.

3. Dec 5, 2008

### GoSS190

The tension force in the rope is working against the force of gravity as well as the force of friction on the block

4. Dec 5, 2008

### LowlyPion

So maybe if you reduce this to an equation ...?