[填空题]
(a) What is the angular6x2phpbq+fn9 +:ib ir momentum of a 2.8-kc;6fm b0ytfq)u/no f6 g uniform cylindrical grinding wheel of radius 18 cm when rotating at 1500 rpm? /tu6)f0yfb m c6 foq;n $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$