Answer
The magnitude of the angular acceleration is $~~16.4~rad/s^2$
Work Step by Step
In part (a), we found that the magnitude of the linear acceleration is $~~4.11~m/s^2$
We can find the magnitude of the angular acceleration:
$\alpha = \frac{a}{R}$
$\alpha = \frac{4.11~m/s^2}{0.250~m}$
$\alpha = 16.4~rad/s^2$
The magnitude of the angular acceleration is $~~16.4~rad/s^2$
