(adsbygoogle = window.adsbygoogle || []).push({});

A 100 kg box is pulled up an inclined plane by a massless, frictionless winch to which it is attached by a massless rope. The plane makes an angle of 45° with respect to the horizontal. The coefficient of friction between the box and the plane is μ = 0.25 (with μs = μk). The winch has a radius of 0.25 m and is turned at a constant angular velocity of ω = 3.14 radians/sec.

How much work is done on the 100 kg box by the rope when the winch makes 10 complete revolutions?

(a) 4380 J

(b) 5235 J

(c) 9262 J

(d) 12531 J

(e) 13620 J

So I did d = [2(.25)(3.34)]10 since we need 10 rev. And then.......

W = mgh + uNd

W = mg(d sin 45) + u(mg cos 45)d

but I'm not getting the right answer, I think I'm suppose to get 13620J, but how do I get that?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Inclined plane with massless, frictionless winch

**Physics Forums | Science Articles, Homework Help, Discussion**