解：由己知t=0.5s =0 a-@o 2Tn 以= 2×3.14× 120 60 =8r/S2 0.5 M=Ja=50×8元=1.26×103N.m 结束目录ω a n t = ω0 = 2π t π 120 2 3.14 60 8 r s 2 × = × = 0.5 M = J a = 50× 8π=1.26×103 N.m 解：由已知 t =0.5s ω0= 0 结束 目录