M=Ja=FR P=J56×102×1.26×102 =47N 0.15 a=M0=fRO =47×0.15×5I=111J 结束目录= = a F R J = 5.6×10-2×1.26×102 0.15 47N A =Mq =FRq =47×0.15×5π=111J (2) M= J a =FR 结束 目录