[填空题]
Pilots can be tested f,i .41lna phit1b rmfv vqp(+7or the stresses of flying highspe, ixds1uon0u 2 k6(brved jets in a whirling “human cd6bs (ux 0inkov,1r2 uentrifuge,” which takes 1.0 min to turn through 20 complete revolutions before reaching its final speed. (a) What was its angular acceleration (assumed constant), $rev/min^2$ (b) what was its final angular speed in rpm? $rpm$