[填空题]
A grinding wheel is a 4oad*z4q6e2 ( zne ctcuniform cylinder with a xsc;7y:+ dk8 og.ssg fradius of 8.50 cm and a mass of 0.580 kg c s+;g7dsosgy.fk:x8. Calculate (a) its moment of inertia about its center, $\approx$ $kg \cdot m^2$ (b) the applied torque needed to accelerate it from rest to 1500 rpm in 5.00 s if it is known to slow down from 1500 rpm to rest in 55.0 s。 $m \cdot N$