[填空题]
A grinding wheel is a u kmzcvz g;4;:ojj18ipniform cylinder1ib- x/wwhg)7j.5w cfa6k 2r6;afqiwb f8nb z with a radius of 8.50 cm and a mass of 0.580 kg. Calculatw2)a ih8fwbc j 1.f zrg-/a6w5;k67 bnfix wqbe (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。 $m \cdot N$