[填空题]
A cooling fan is turnedd5 cjirs3ws9( off when ilz;)z ) hs45k 8ojdzgtt is running at 850rev/min It turns 1500 revolutions before it zlozg4 ) )tkz5j8dsh; 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