[填空题]
(a) What is the angular momentum of a 2.8. v6imxvi -v7v-kg ua: swo-adcf)i1. u5umniform cylindrical grinding wheel of radius 18 cm when rotating at aw)umcd-1suf5. oai :1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$