Change in magnitude of radial acceleration

[alexmahone]

Homework Statement

A wheel changes its angular velocity with a constant angular acceleration while rotating about a fixed axis through its center. Show that the change in the magnitude of the radial acceleration during any time interval of a point on the wheel is twice the product of the angular acceleration, the angular displacement, and the perpendicular distance of the point from the axis.

Homework Equations

$$a_r=\omega^2 r$$

The Attempt at a Solution

I really don't know. Please help.

 

[alexmahone]

Got it, never mind.