[填空题]
A grinding wheel is a uniform cylinder with a radius of 8.6e0 rik3g2s ep ;c:2d; -yhdfenbss g250 cm and a mass of ay xf3tggb3*px -e9eo a.,ntpgai4060.580 kg. e y3optp xga3*x9e6ag0 a4- f.nb,gi tCalculate (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。 $m \cdot N$