[填空题]
A grinding wheel is a uniform cylinder with a e8zh +z5 1ngqdz*oe6f radius of bbzk5 : qqqjq5(-p6op 8.50 cm and a mass of 0.580 kg. C6qoq(5bk -qzpb5jp :qalculate (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。 $m \cdot N$