大学物理 英语版课件.ppt

《大学物理 英语版课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Chapter1ParticlekinematicsAgeometricalpointwithcertainmassTheshapeandthesizeofthebodyCouldbeneglected.MassisthemostimportantWhatisparticle?IdealModel§1-1displacementandpathReferenceframeobjectpoint1.BasicconceptsPositionVectorO:referencepointP:particlepositionPo

2、sitionvectorMotionEquationDisplacementOA,t1B,t2displacementPathOA,t1B,t2Locusequation:Displacement:Vector,withbothmagnitudeanddirectionPath:nonnegativescalarVectors&scalarsVector:physicalquantity,specifiedbybothmagnitudeanddirectionscalar:quantity,specifiedbyapo

3、sitiveornegativenumberwithappropriateunitTemperature,volume,mass,time,pathDisplacement,forceSomepropertiesofvectors1.EqualityoftwovectorsThesameunit,thesamemagnitudeandthesamedirection2.AdditionABA+BParallelogramruleofadditionABA+BTrianglemethodofaddition3.subtr

4、action4.multiplicationDotproductofvectorsCrossproductofvectorsDisplacementvs.PathInitialcoordinatesFinalcoordinatesThedisplacementofaparticleiscompletelyknownifitsinitialandfinalcoordinatesareknown.Thepathstrictlydependsonthelocusoftheparticlemotion.Thedisplacem

5、entisindependentofthepath2.ExpressionofpositionvectoranddisplacementXYOPPositionvectorplaneright-angledcoordinatesExpressionofthepositionvector)θRight-angledCoordinatesSystemxyzoX-axisorabscissaY-axisZ-axis原点:origin象限：quadrantPolarcoordinatessystem(,)Ballcoord

6、inatessystem(R,,)zoRxycolumncoordinatessystem(R,,z)zRMagnitudeofthepositionvectorangularposition/directionangleXYOP)θExample:Ahikerbeginsatwo-daytripbyfirstwalking25.0kmduesoutheastfromhercar.Shestopsandsetsuphertentforthenight.Ontheseconddayshewalks40.0km

7、inadirection60.0onorthofeast,atwhichshediscoversaforestranger’stower.(a)determinethehiker’sdisplacementsonthefirstandsecondday.(b)determinethehiker’stotaldisplacementandpath.Solutionsetupaplaneright-angledcoordinate,denotingthedisplace-mentvectorsonthefirstandse

8、conddaysbyAandB,respectively.cartentA)-45otowerB)60ocartentA)-45oThedisplacementofAis:(a)ThemagnitudeofdisplacementofAis25km.cartent17.7,-17.7towerB)60o(a)Similarly,t