[填空题]
Pilots can be tested for-t4-rypqec( b the stresses of flying highspeed ja;ctx-p9c xs7lrk.ay*5 uh kr41nuk2ets in a whirling “human centrifuge,” which takes 1k.y7a54k ht;au9rxl ckxs n12pu rc-* .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? $rpm$