[填空题]
(a) What is the angular momentum 0+qvp5tf;e majv) x,e of a 2.8-kg uniform cylinyp(03 qhox icbti9+ o/drical grinding wheel ofpio(3cqt0i/9y +ohb x radius 18 cm when rotating at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$