[填空题]
A cooling fan is turned off when it is running at 850rev/;zgfu +mj2jna ,rivn7+ g +-eymin It turns v;iy/4 l jpsd)j(1jcd1500 revolutions before it comes top41j(s yd)jj/vicd; l 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