[填空题]
(a) What is the angu;ca owc2-m0h slar 6oz qbzq, n3fg,hr)z3momentum of a 2.8-kg uniform cylindrical grinding wheel of radius 18 cm when rotabq,g3) , 6 qrhzozfnz3ting at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$