# Angular Accerlation

## Homework Statement

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?

## Homework Equations

Change in Angular Accerlation/ Change in time

## The Attempt at a Solution

I tried the above equation but the online homework says the answer is wrong. I'm not sure of what else to do.

$$\alpha=\frac{\Delta \omega}{\Delta t}$$