理论力学全套解疑13

ma=∑FOr22ddtraFr∑=22ddtmzyxFtzmFtymFtxm∑∑∑===222222ddddddnnFsmvmmaFtsmtvmma∑∑======ρρττ2222ddddbbFma∑==0ϕϕϕϕϕFttrtrmmaFtrtrmmarr∑∑=⎥⎦⎤⎢⎣⎡−==⎥⎥⎦⎤⎢⎢⎣⎡⎟⎠⎞⎜⎝⎛−=dddd2dddddd22222r=r(t)x=x(t)y=y(t)z=z(t)s=s(t)13-3113-3213-3313-3113-3213-3313-4F13-4aAA113-4bFFmax=k|xmax|OvmaxP=2Q13-5113-52AMJ=ϕ13-5113-5213-5313-54113-5113-53T=P=2QAggQQTQQgQTa=−=−=213-52TAB13-54ab)QTagQ−=(1)TPagP−=(2)P=2Q(2)1gaQT3134==APPMmlOα13-6aTa13-6b∑==0ττFma(1)∑==αsinTFmann(2)∑−===mgTFmabbαcos0(3)ab=0(3)αcosmgT=13-6(2)ααtgsingmTan==αsin2lvan=Mααcossin2glv=mvRµx13-7xxmxxmxxmµµµ−=−−==Rma=RRvRR=µvma=µvxmax=−µvxxxmµ−=∑=Fam13-8113-82∑=Fammkl013-81OxkxFxm−=−=(1)02=+xxω1mk=2ω1)sin(αω+=tAx(2)2OX13-82)(0lXkFXm−−=−=(3)022lXXωω=+(3)mk=2ω(3)XtAX++=)sin(αωX(3)(3)X=l00)sin(ltAX++=αω(4)(4)OX(2)(4)mMFRa13-9)FRxmRFxmRFxm−=−=−mmm+=−=−−=−=RFaRFaFRaF=−F′F′ma=F+RFxFyFzaxayazvxvyvzFτFnFbaτanabma=F+ROxaxxxRFma+=xFxRxaFROxFOxFx=FFFROxRxRx=−RRRaxxxxxRFma+=RFxm−=aaxx−==aaRFxm−=m(−a)=F−Rma=R−F