[填空题]
A cooling fan is turnedh:;d+asz/j xmn,g3 (edvk.549cvrgiiwjj2 o off when itn-(cq25 6t k dsg)xxms is running at 850rev/min It turns 1500 revol-52cx(tdsqn6) xm gksutions 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