[填空题]
A cooling fan is turned off wo1st+w+ y*tnb hed,swh7c n+m h-n it is running at 850rev/min It turns 1500 revolutions before it comes todws7ncm- hh+ , 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