工程力学双语课件ch03-Equilibrium-of-Concurrent-Forces-in-a-Plane

um.ABCDF1F2F3F4F4F3F2F1F1F1F2F2F2F3F3F3F4F4F43.2ActionandReactionNewton’sthirdlaw:actionandreaction3.3Spacediagram,Free-bodydiagram.3.3.1Aboutspacediagram.3.3.2AboutFree-body.3.3.3AboutFree-bodydiagram.3.4Constructionofafree-bodydiagram.3.4.1.Afree-bodydiagramshouldinclude:1.Anygivenanglesanddimensions2.Allforces,includingweights,andthosemagnitudeanddirectionsarespecifiedorimplied.3.Anyunknownanglesandforces.3.4.2Example.Example3.1(P68).Example3.2(P71).Example3.3(P71).Example3.4(P72).Example3.5(P73).3.4Constructionofafree-bodydiagram.3.4.3Problems.Dotheproblems3.1-3.8byyourself,andthenIwilltellyoutheanswersofthem.3.4Constructionofafree-bodydiagram.3.5Threeconcurrentforcesinequilibrium.pletedtriangle:1.Vectorsmustbeaddedinatail-totipfashion.2.Forequilibriumtoexist,theresultantmustequalzero.