[填空题]
A cooling fan is turned off when it ikp l/*e+i1co)f93 .ndoq m/lmq f qa4ps running at)0s/yjaa 1y nu 850rev/min It turns 1500 revolutions before it comes to a stop. j1)0/aya usny (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