[填空题]
A cooling fan is turned off wh k22+xgiqqu: ten it is running at 850rev/-c 3fxidyls (x yy)bxw8j5*9omin It turns 1500 revolutions befo-)x3 jy o9(8dys5cxbfy *xliw re 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