[填空题]
(a) What is the angular(lgdw8 wfa* t) gha,t8of1fsfo 2ih* 5 mom ex ; fvfv8 r)v5xqrr/jz:7g0centum of a 2.8-kg uniform cylindrical grinding wheel of radius 18xcvgrez 5fq x)vj:r 80rv;/f7 cm when rotating at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$