Chapter 11 - Rolling, Torque, and Angular Momentum - Problems - Page 326: 71b

$\alpha = 16~rad/s^2$

In part (a), we found that the magnitude of the acceleration of the center of mass is $a = 1.6~m/s^2$ We can find the magnitude of the angular acceleration about the center of mass: $\alpha = \frac{a}{R}$ $\alpha = \frac{1.6~m/s^2}{0.10~m}$ $\alpha = 16~rad/s^2$