[填空题]
A cooling fan is turned o) :kdlt kp9vv bx7p65 jn8(zaqff when it is running at 850 +ovdkxt9 0u :w2fdp0rrev/min It turns 1500 revolutk t w20ddxr+9u:f0 vopions 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