[填空题]
(a) What is the angular 2lde to9nbum( 3 4m 9-h7whnqjmomen3);go zl9ijjwyg+ ee, tum of a 2.8-kg uniform cylindrical grinding wheel of radius 18 cm when rotat,;3ejoj i 9 ly)+zwggeing at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$