[填空题]
A cooling fan is turned off when it is running v;wbudwc n5h: z a;)6gat 850rev/,n2 2lx)o ihvpmin It turns 1500 revolutvn2 lo,pxh)2 iions 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