[填空题]
An automobile engine slows down from 45.y4w+setj7w t 00 rpm tza2qujr3i 6wr k(nwy *d3 gl2:o 1200 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. $rev$