[填空题]
An automobile engine slows0 ay6dp1biwnr4u *4k p down from 4500 rpm to 12ta*dkl v c/n3:yump0+00 rpm in 2.5 s. Calculate (a) its angular acceleration, assumed constant, $rad/s^2$ (b) the total number of revolutions the engine makes in this time. $rev$