[填空题]
A grinding wheel is +06b;u oazbw xa uny) 86qni 4fdruj n3zh5iform cylinder with a radius of 8.50 cm and a mass of 0.580 kg. Calculate j 4du3yhf86inzrq)n5 (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。 $m \cdot N$