[填空题]
A cooling fan is turned off when+eaju/s(dq, p ,nybx0k l(l(h it isz *6dlqinq; ll ;un(; c5ws)ms running at 850rev/min It turns 1500 revolutions befonnlswq l5dl*;c;6z q;( u si)mre 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