# Homework Help: A fun new circular motion question!

1. Sep 17, 2008

### Garen

Ok, so I set 9.8=v^2/r , therefore v=$$\sqrt{9.8r}$$. I converted r from miles into meters and got 3459.35. This seems like an easy enough question, but for some reason I keep getting it wrong. The answer I keep getting is 184.12395m/s, but the question asks for it in rad/s. I've looked everywhere on how to convert m/s to rad/s, but no luck. I don't know if the problem is the conversion or my method in attaining v. Also is v=angular speed? Thanks in advance to all you physics geniuses out there.

2. Sep 17, 2008

### Garen

3. Sep 17, 2008

### Dick

v is linear speed in m/s. The angular speed in radians/s=v/r.

4. Sep 17, 2008

### Garen

So what you're saying is that I set 9.8=v/(radius of cylinder) ?

(3459.35)(9.8)=v

Is this correct?

5. Sep 17, 2008

### Dick

No, no, no. You found v. The angular velocity is v/r.

6. Sep 17, 2008

### Garen

Could you define r?

7. Sep 17, 2008

### epheterson

2.15 mi.

Last edited: Sep 17, 2008
8. Sep 17, 2008

### Dick

The same r you used in v^2/r. It's your notation.