[填空题]
A cooling fan is turned off when it is running at 850rev/min4eiyd ;rcim 6y8 qg.*l It turns 15 9 1zwnbgj6pp4/sk7fr00 revolutions before it comes /f 4npj1pg7ksr69zbw 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