[填空题]
A cooling fan is turned off when it is runov im,q:( .cvsning at 850rev/min It turns 1500 toon o.):we5ygy 12bu revolutygy1bo 5o2:o) tw n.euions 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