[填空题]
A cooling fan is turned off when it is runniatl8b77mut1nx 8bk *gng at 850b61:hn-oo sa mrev/min It turns 1500 revolutions before it comes6nma 1o:-sbo h 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