[填空题]
A grinding wheel is a uniform hc+yn 3yiy:f8g(fwhlg*2o iccc .::w cylinder with a radius of 8.50 cm and y*100(a d rdfe6xv . ataoipr;a mass of 0.580 kg. Cirf;a( rxd*1t.p yavo da0e06 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。 $m \cdot N$