[填空题]
A grinding wheel is a uniform;o.dzrh m17 jq cylindesv60rv 4j-v oyg1 gxf 9qgbupo+l72n 0r with a radius of 8.50 cm and a mass of 0.580 kg. Cnpg6jv 1+b2qlg49v7yxo00g rfo uv- salculate (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。 $m \cdot N$