[填空题]
A grinding wheel is a uniform cyl-wjh)h1t;; jp1bqm933c ffodiogzp8inder with a radius ofh+*)4khqf kpvpcg 8w+7.ea0 l algx (s 8.50 cm and a mass of 0.580 kg. Ca .l7( l+q *gpc8k+wavk sxeafh0ph)g 4lculate (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。 $m \cdot N$