[填空题]
A cooling fan is turned off h l2enh.e v5t :s; *ayq/e5+q(uzjkjtwhen it is up66wm +tw2bo running at 850rev/min It turns 1500 revolutions before im662wwb puot+ t 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