1、123),2,1(0),(11nktfnkrrr),2,1(),(21nitqqqNii rr),2,1(12211niqqqqqqqqNkkkiNNiiiirrrrrkq4niFiFWW10111111 kNknikizikiyikixiniNkNkkkiziNkkkiyikkixiqqzFqyFqxFqqzFqqyFqqxF),2,1(1NkqzFqyFqxFQnikizikiyikixik01NkkkFqQW501NkkkFqQW021NQQQ6),(111nnnzyxzyxVViziiyiixizVFyVFxVF,VzzVyyVxxVzFyFxFWiiiiiiiziiyiixiF)()
2、(00V7),(21NqqqVV),2,1(NkqVqzzVqyyVqxxVqzFqyFqxFQkkiikiikiikizikiyikixik),2,1(0NkqVQkk80V),2,1(0NkqVk91011121314150V),2,1(0NkqVk0dqdV022dqVd),2,1(1NkqzFqyFqxFQnikizikiyikixikNkkkFqQW1),2,1(0,0kjNjqqjkkkFqQWkFkqWQ),2,1(NkqVQkk017 cossinlrh)cossin(22lrPPhV0VQ180)sinsincos(22lrP即：0tantan23rrl改写为：19 图示系统
3、，A重2P，B重P。不计滑轮重及O、E处摩擦，求平衡时C的重量W及A与水平面之间的摩擦系数 f。解：解：系统具有2自由度。以sA、sB为广义坐标（1）当sA改变sA而sB=0（B不动），此时sC=sA/2ACAAsWFsWsFW)21(WFsWQAAA2120 （2）当sB改变sB而sA=0，此时sC=sB/2BCBBsWPsWsPW)21(WPsWQBBB21系统平衡时有QA=QB=0由QB=0 得 W=2P由QA=0 得 F=W/2=P212PFf21),2,1(0 NkQqTqTdtdkkkniiivmT1221kqkq kQ22),2,1(0 NkqVqTqTdtdkkkVTL ),2
4、,1(NkqVQkk),2,1(0NkqLqLdtdkk23242526rrRrvAA)(2(21)(213)(212222222221rrRrmrRmrRmT2221)(92(121rRmm27OOMMQQTTt)(ddOMrRmm 221)(92(61221)(92(6rRmmMO 28293022212121BABAvmvmTTT)cos2(2121222221l xlxmxm)cos2(2121re2r2e221vvvvmxm cos21)(212222221x lmlmxmm310sincos)()(ddcos)(22221221xTlmlmxmmxTtlmxmmxT sinsinc
5、os)(ddcos22222222 x lmTx lmx lmlmTtx lmlmT320 xWQxxQTTtQxTxTtx)(dd,)(ddsinsin22glmglmWQ33)b(0 sin cos)a(0 sin cos)(22221lglxlmlmxmm 343536222221121212121BEACJygWJxgWT)(1,11xyrRxBA222121,21rgWJRgWJECx1yE37yxgWygWxgWygWxgWT1222212222112141412143yWxWV211sinyWxWyxgWygWxWWgL21112212121sin2143)3(41x1yE38)b(23)a(sin2)3(112121gyxgWyWxWW gWWWWygWWWWx212121211292)sin3(2292sin6 0)(dd,0)(dd11yLyLtxLxLtyWxWyxgWygWxWWgL21112212121sin2143)3(4139
