[填空题]
An automobile engine slows wgbk,-e g qk.7down from 4500 rpm to 12s:cb k0ec52wezl( eambn8. :n 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. $rev$