[填空题]
A grinding wheel is ; xdsi58;fh(uq, 6msl7m g wgxa x*a fe g1dw/ mr2s2b1auniform cylinder with a radius of 8.50 cm and a mass of 0.fwabm2sd 1 *a 2x1reg/580 kg. 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。 $m \cdot N$