[填空题]
A cooling fan is turned off when it d.i5g(cg0m8 7 wtuujhqu0f s /is ru3ut-lhd6 cf,qd z+r x)nning at 850rev/min It turns 1500 revolutions before it comqld6r+c 3-zxdu,th f)es 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