[填空题]
A cooling fan is turned off when it is ;)uf zktfwl2*running at 850rev/min It turnslw qx-i/9b,4 .bpn kih7 dmqcz;-bf +z 1500 revol ,w-/fiki dpc;qm9.b7nql+ bh -4zb xzutions 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