[填空题]
(a) What is the angularv bv ne//jc(9k momentum of a 2.8-kg uniforj:5i0rsvrh6esyrf) 6m cylindrical grinding wheel of radius 18 cm when ro v50)se ry:ifr rsh66jtating at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$