[填空题]
A cooling fan is turned off when it is running akawh 1w2 s1(, kv bjr(zf3h2 o;h5dazqt 85 ry6k*y8f tj/y; :pvzk0rev/min It turns 1500 revolutions befo frt yzy*/k6v:p j;y8kre it 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