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4、FFFFFF 2134)(MMdFFFdM 0 iM inMMMMM21？aaABCaBCABFBFCFABF 02,0 aFMMAMFFBA22 MFFFBBC22 M1M2CABDM2CDM1AB FB FA FC FD030cos,01 MaFMBaFMB231 030sin,02 aFMMCaFMC212 321 MM0,0 aFMMAaMFFBA EDCBA FBDBC CF DF MDE FE FDCAE FC EF 045sin,0 MaFMDaMFFED2 51sin045cossin,0 ECyFFFaMFC5 EDCBA1F 2F 1F2FPRMoAMMBC结论与讨论结论与讨论cosFx FjiFyxFF iRFF RRyRRRxRyixiRyRxRFFFFFFFFF),cos(,),cos()()(2222jFiF0 iRFF00 yixiFFOABdFMO2)(F)()()()()(21iOnOOOROMMMMMFFFFF 力力偶偶矩矩 FdM0 iMiMM
