What is the Work and Friction in This Incline Scenario?

[marker403]

Homework Statement

A worker pushes a 93N crate 10m up a 37 degree incline with constant velocity. The worker exerts a force of 85N parallel to the incline.

a. How much work does he do?
b. How much work is done by gravity?
c. How much work is done by friction?
d. What is the coefficient of friction between the box and the incline?

Homework Equations

Work = Force x Distance
Ff = (u)(Fn)

The Attempt at a Solution

Part A:

work = (85 N)(10 m) = 850 joules

Part B:

work = (10 * sin(37)) * 93 N = 560 N

I believe these are correct. The parts that I do not know how to do are C and D. Anyone know how? I greatly appreciate all help :)

 

[G01]

HINT:

The net work done by non conservative forces (i.e. the force of the push and friction) will equal the negative of the change in energy of the box:

W_{non-conservative}=-\Delta E

Can you use this to find the answers for parts C and D?

 

[marker403]

Thank you for your help!

So the force of friction is -850 joules?

For Part D, I am supposed to use the friction force for Ff and the normal force for Fn, right?

Is the normal force 93 N?