[填空题]
A cooling fan is turned off when it is running at 85vlt9h7 a 5we5t0rev/min Izpv)n4rboj49 t turns 1500 revolutions vjb4o4rz)pn9 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