[填空题]
A cooling fan is turned off when it , z+msb93dxy4h nzh.cis running at 850rev/min It turns 1500 rev9v cxr-gspu (+olutio-gcvps9x u r+(ns 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