[填空题]
A cooling fan is turned off when it igd7w+1u g6xgz s running at 850rev/min It turns 1503, kab0)km u 4dzp:ufu0 revoluuk3d4f u,m)ak:pb 0z utions before it comes to a stop. (a) What was the fan’s angular acceleration, assumed constant? $\frac{rad}{s^2}$ (b) How long did it take the fan to come to a complete stop? s