[填空题]
A grinding wheel is (v18.ujiaoz d /sdvh4+axuz/c)jschy /hc;( a uniform cylinder with a radius of 8.50 cm and a mass of 0.580 kg. Cchh +/sduccsa(z;/ hvjx)y 4 /alculate (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。 $m \cdot N$