[填空题]
A cooling fan is turned off when it h: 7)tdkrr2louc r+9z is running at 850rev/min It txac2/wv -ka:t urns 1500 revolutions before i/c2tav- x:kwat 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