[填空题]
A cooling fan is turarsjv ;p06uf7ned off when it is running u83nep ;gygg+qc h w3b0vg3cj m-95,j xajm) hat 850rev/min It turns 1500 revolutions before it comes to a stopg3vj)-m;q83a gw5ghxcb jyc,hgu jme03+9np . (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