# Torque to accelerate?

1. Oct 13, 2008

### Duely Cack

1.How much torque is required to accelerate a phonograph album (75-g, 30-cm diameter 33.3 rpm) at 3-rad/sec2

2. T=I(alpha)

3. Sorry i have to idea on this one im completely lost!

2. Oct 13, 2008

### Rake-MC

$$\tau = I\alpha$$ as you stated.
You are given $$\alpha = 3 \theta s^{-1}$$
So just multiply by moment of inertia.

Hint: For a disc it's $$I = \frac{1}{2}MR^2$$

3. Oct 13, 2008

### D H

Staff Emeritus
Rake, you are not helping here. The OP should know some of this stuff, or should at least know how to look it up. When you give out too much information you are helping students get their homework finished (you are doing it for them, for free), but you are not helping them learn.

4. Oct 13, 2008

### Duely Cack

Well the fact that I dont own a physics book and My teacher only gives us equations with variables for numbers and variables for more numbers and only gives examples of when used in real life. i would say that at least that is teaching me something thanks rake it helped me get that problem done on to the next one that was easy b/c of your help