[填空题]
An automobile engine slows down from 4500 cje x;7*f.c h*gui2 vyrpm to 1200 rpm in 2.5 s. Calculate ;spp1 knm 0p+3) cf80hado08wenzgoy (a) its angular acceleration, assumed constant, $rad/s^2$ (b) the total number of revolutions the engine makes in this time. $rev$