[填空题]
(a) What is the angular mome(0 t: 60nvmrz5y w0/ecocwyv rntum of 3bjehy y avx:41ak-sn3d2nx 8a 2.8-kg uniform cylindrical grinding wheel b2sy:4 3 edaakxy18vh3 j-nnxof 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? $m \cdot N$