[填空题]
A cooling fan is turned off when it is runnact7r; x5ka ag8/ 6e0lpa6 zeoi: ;vyktb x68 q*thyo+jng at 850rev/min It turns 1500 revolutiyb;yt+ jqo*h:6xk8vt ons before 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