[填空题]
An automobile engine slows down from 4500 rpm to 1200 rpm in u*2ju7cgtdbo)fi:* o 2.5 s. 94j+okr3 nv: hyy-uxz Calculate (a) its angular acceleration, assumed constant, $rad/s^2$ (b) the total number of revolutions the engine makes in this time. $rev$