[填空题]
A cooling fan is turnypxyw: g(4a4bh 55n .mfaj6bfeogrc(s;+k, h3emw6v nd off when it is running at 850rev/min It turns 1500 revolutions before it c(n,;ovr k3+ cm gw6sheomes 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