[填空题]
(a) What is the angular momat ccgk81icy5b) q)l8tl .mnyq lpb m;:ig9 :7;sp9vgentum of a 2.8-kg uniform cylindrical grinding wheel of radius 18 cm when rotatibq:;gpt.np mll9 :g7;s y vm9ing at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$