[填空题]
(a) What is the angulwr)je cvsj :(rud q064(mz em3m*x0uzar momentum of a 2.8-kg uniform cylindrical grinding g el t*hs2d9ql4 c(lk6kkl;+ pwheel of radius 18 cm w g(2+ slkqh;l6l9ltdep k*kc4hen rotating at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$