[填空题]
A cooling fan is turn/f8u yb4gj0p nnmma q(z92u0m ed off when it is running at 850rev/min It turns 1500 revolutions before it comes (mu qammn 20z9to 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