# Angluar acceleration of a computer disk

1. Feb 13, 2008

### cstout

1. The problem statement, all variables and given/known data
During normal operation, a computer's hard disk spins at 7200 rpm. If it takes the hard disk 3.7 s to reach this angular velocity starting from rest, what is the average angular acceleration of the hard disk in rad/s2?

2. Relevant equations

Wav = $$\vartheta$$f - $$\vartheta$$i/Tf-Ti

3. The attempt at a solution

2. Feb 13, 2008

### kamerling

you want: Wav = ($$\vartheta$$f - $$\vartheta$$i)/(Tf-Ti)

Do you know what all the variables in this equation mean? It is the right equation so you just have to find out what all the variable are in express them in the right units

3. Feb 17, 2008

### cstout

I got it now, I didn't convert the 7200 rpm to rad/s