[填空题]
A cooling fan is turned off when it is running at 850re4 ylbqb k-r*z+m1rz/k )vsyk 3v/min It turns 1500 reiwcz,g :y+hb9na,gn -volutg cw,a+,hyb z-g:9nniions 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