# Angular physics problem

1. Mar 27, 2005

### Punchlinegirl

An astronaut is being tested in a centrifuge. The centrifuge has a radius of 8.5 m and in starting, rotates according to theta= .21t^2, where t in seconds give theta in radians. When t=5.0 s, what are the astronaut's angular velocity?

I did .21(5.0)^2 / 5, to get angular velocity, but it was wrong. Can someone steer me in the right direction?

2. Mar 27, 2005

### whozum

I have no idea what equation that is that your using.

$$\theta(t) = .21t^2$$

$$\omega(t) = .42t$$

by the relationship $$\omega(t) = d\theta(t)/dt$$

Last edited: Mar 27, 2005
3. Mar 27, 2005

### dextercioby

Why do they give the radius,if they don't ask for the tangential speed...?

Daniel.

4. Mar 27, 2005

### whozum

Probably needs help on just one part of the problem.

5. Mar 27, 2005

### Punchlinegirl

Ok I see what I was doing. Thanks so much