[填空题]
(a) What is the angular momentu-b 5n), wvgqwfm of a 2.8-kg u5hk1/dds1 u uehtvp rezm) 30uq.07toniform cylindrical grinding wheel of radius 18 cm whekz1 )5 st0m .730urhqodupv t1ud/hee n rotating at 1500 rpm? $kg \cdot m^2$ (b) How much torque is required to stop it in 6.0 s? $m \cdot N$