[填空题]
A cooling fan is turn2o 25liedbc-bk/v op) : nn03gve0iqzyjlcm 34 )p:mied off when it is running at 850rev/min It turns 1500 revolutions before it comes to a stoj)c 3ym4i :lpmp. (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