A 100 lb block of ice slides down an incline 5.0 ft long and 3.0 ft high. A worker pushes up on the ice parallel to the incline so that it slides down at constant speed. The coefficient of friction between the ice and the incline is 0.10.

Question

Find (a) the force exerted by the worker, (b) the work done by the worker on the block, (c) the work done by gravity on the block, (d) the work done by the surface of the incline on the block, (e) the work done by the resultant force on the block, and (f) the change in kinetic energy of the block.

I solved a and b, and I get them, but I'm stuck conceptually on the last few parts. On c, my biggest issue is that I think I'm confusing this situation to one where a block attached to a string is lowered (i.e. negative work is done on the block.)

Does (d) even matter since it's not the incline pushing the block down it? Or does friction play a part here?

For (e), if Fnet is 0 (since all the forces have to be 0 for there to be constant speed) does that mean this question is irrelevant?

...I can figure (f) out on my own.

I don't want answers, just...some conceptual help on this one.