# Torque, Angular Displacement, Work

1. Oct 18, 2011

### warrior2014

Torque, Angular Displacement, Work!!!

1. The problem statement, all variables and given/known data
The radius of a wheel is 0.525m. A rope is wound around the outer rim of the wheel. The rope is pulled with a force of magnitude 5.45 N, unwinding the rope and making the wheel spin counterclockwise about its central axis. Ignore the mass of the rope.
a) how much rope unwinds while the wheel makes 1.00 revolution?
b) how much work is done by the rope on the wheel during this time?
c) what is the torque on the wheel due to the rope?
d) what is the angular displacement Δθ, in radians, of the wheel during 1.00 revolution?
e) show that then numerical value of the work done is equal to the product τΔθ

2. Relevant equations

T= F*R

3. The attempt at a solution

I have no idea how to get this problem started. If anyone is able to help, please do so (I know there are a lot of parts to the question)! I'd really appreciate it :)

2. Oct 18, 2011

### SammyS

Staff Emeritus
Re: Torque, Angular Displacement, Work!!!

Are you saying you can't answer part (a) ?

3. Oct 19, 2011

### warrior2014

Re: Torque, Angular Displacement, Work!!!

I figured out how to get (a), (b), (c) and (e) but unsure how to get (d). Could you please help me with that one?

4. Oct 19, 2011

### SammyS

Staff Emeritus
Re: Torque, Angular Displacement, Work!!!

How did you get (e) without getting (d)?

5. Oct 19, 2011

### warrior2014

Re: Torque, Angular Displacement, Work!!!

well the work done is going to be the same and since I knew that, I put the value in and it was correct

6. Oct 19, 2011

### SammyS

Staff Emeritus
Re: Torque, Angular Displacement, Work!!!

The quick way to answer (d) is to realize how many radians correspond to one complete rotation of the wheel.

7. Jun 24, 2012

### warrior2013

Re: Torque, Angular Displacement, Work!!!

how would you do part a?