[填空题]
(a) What is the angularu5)m k68zfj4,qqx sfn momentum0 zj bf9h* z6z.zn5dzj of a 2.8-kg uniform cylindrical grinding wheel of radius 18 cm when rotating at 150 5dznzz f9.zb*j 06jhz0 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$