[填空题]
(a) What is the angular momentum of a 2.8-kg uniform cylisr8amcsa+zm rv0djm* 6(+m.n ndrid kkqi5l9/buz ajy69fo or 2k).u:xa3cal grinding wheel o 5kj3yaz/9o :u)9kkxa f bli26d.uro qf 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? $m \cdot N$