物理科題目1 求解?

At t=2 s, angular velocity of the wheel = (41.3 + 17.6 x 2) rad/s
= 76.5 rad/s

Since the wheel stops under constant decceleration, the mean velocity of the wheel = 76.5/2 rad/s = 38.25 rad/s

Hence, time taken for the wheel to stop = 432/38.25 s = 11.29 s
Therefore, time at which the wheel stops = (2 + 11.29) s = 13.29 s