[填空题]
A cooling fan is turne/3 fozr42cct.n 47mlm t5szhyd ofg2cvx /6zf 1fyf when it is running at 850rev/min It turns 1500 revolutions before it comes to a stovcyxg6 f1/zf 2p. (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