课件物理下讲稿

15班，16班，17班，18班的同15班，16班，17班，18班的同学们：新年好UniversityPhysicsText《PrinciplesofPhysicsbyWalker,Halliday&(10thedition)Wiley，第十GeneralPhysicsII,Ch21--Office：Room212(第二科研楼) 88018225 CourseUniversityPhysics (大学物理,下•CourseUniversityPhysics (大学物理,下•••Course 《Principlesofphysics》(10thedition)第十III.CourseLanguage:5Bonuspoints(In-classtests，simple2IV.CourseAssessment（成绩评估Inclasstests(quiz) 60%(学期中有4次测验)Selectedhomework 10%(迟交不给分)Final 30%(期末考试必须参加••2:00pm—3:50pm(周二，下午2:00pm—3:50pm(周四，下午•(PPTavailableonlineafterclass)QQgroupforall3VICourseVenue:Lectures(大班:RoomTutorials(小班)Class15tobeClass16(inRm?)Class17(inRm?)Class18(inChapterscoveredinspringsemester(March-ChapterChapterChapterChapterChapterChapterChapterChapterscoveredinspringsemester(March-ChapterChapterChapterChapterChapterChapterChapterChapterChapterChapterChapterChapter(静电场(高斯定律(电势(电容Coulomb’slawElectricFieldsGauss‘LawCurrentandMagnetic(磁场MagneticFieldsDueto(电流激发的磁场(电磁感应与电感InductionandElectromagneticOscillationsandAlternatingCurrent(电磁振荡与交流电)Maxwell’sEquations(麦克斯韦方程),MagnetismofMatter(物质的磁性)ChapterElectromagneticWaves(电磁波Chapter ChapterChapterDiffraction(衍射)ChapterRelativity爱因斯坦狭义相对论IntroductionofQuantumMechanics(量子力学简介GeneralPhysicsII,Ch21-22-Attending Preview(ReadbookbeforeAttending Preview(Readbookbefore Takingnotesin Weekly6-10hoursworkafterclassReviewPPT&text Do 5Inspirationalquotes(励志名言byWhenitisgettingitisthetoughthatgetsDiscusswithyourfellowclass Ask WhattodotosucceedinthisOne(第一讲ChapterCoulomb’sOne(第一讲ChapterCoulomb’slaw库伦定律Electriccharge(电荷propertiesofelectricElectrostaticforceandCoulomb’sElectrostaticforce(静电力Coulomb’slaw(库仑定律electrostaticforce(叠加原理(III)Superpositionprinciple6TherearefourfundamentalforcesinTherearefourfundamentalforcesinStrongforce(强力Weakforce(弱力GeneralPhysicsII,Ch21--1.Electriccharge电荷andchargedobjects(带1.Electriccharge电荷andchargedobjects(带电体(I)ElectricGeneralPhysicsII,Ch21-22-LikeKg,m,s,theunitCisoneoffivebasicSIunitsTherearetwofundamentalchargecarriers(载电体electronandproton，whichcarrytheleastamountofchargeof1.6×10−19𝐶(II)Conductorand(II)ConductorandGeneralPhysicsII,Ch21-22-Insulator(绝缘体freetoConductor(导体Conductorsarematerialsinwhichasignificantamount(III)Propertiesofelectric(III)PropertiesofelectricGeneralPhysicsII,Ch21-22-𝒆1.610−19𝐶isthesmallestmagnitudeofachargewhichcouldn’tbefurtherdivided.Thisiscalledthequantizationofelectriccharge(电荷的量子性).ItwasdiscoveredbyRobertA.Millikan(1923Nobel-+GeneralPhysicsII,-+GeneralPhysicsII,Ch21-22-Anexample:TwopositiveorAnexample:Twopositiveortwonegativechargesrepeleachother.Apositivechargeandanegativechargeattracteachother.GeneralPhysicsII,Ch21-22-bConservationofelectricCharge电荷量守恒bConservationofelectricCharge电荷量守恒TotalnetelectricchargeforasystemofnGeneralPhysicsII,Ch21-22-Relativisticinvarianceofelectriccharge(相对论不变性𝑚(𝑣1)≠Relativisticinvarianceofelectriccharge(相对论不变性𝑚(𝑣1)≠GeneralPhysicsII,Ch21-22-𝑞 =But,themagnitudeofachargeisnotvelocitydependent,itisirrelevanttotheobservingreferenceframeThisiscalledtheRelativisticinvarianceofelectriccharge(相对论不变性)WeknowfromEinstainrelativity(爱因斯坦相对论thatthemassofanobjectdependsonitsvelocity,orwecansaymassisdifferentobservingfromdifferentframeofreference(参考系):𝑚 =𝑚 1 Example-AtomsandApositiveionisanExample-AtomsandApositiveionisanatomwithoneormoreelectronsAnegativeionhasgainedoneormoreAneutralatomhasthesamenumberofprotonsaselectrons.GeneralPhysicsII,Ch21--Millikanoil-dropexperiment(电荷的量子性实验证明Millikanoil-dropexperiment(电荷的量子性实验证明RobertA.Millikan1923Nobel-------+-GeneralPhysicsII,Ch21--Inthisexperiment,hefoundthevaluesofqwerealwaysgivenbyq=forn=0,±1,±2,inwhicheturnedouttobethefundamentalconstantwecalltheelementarycharge,1.60X10-19C.Video3&Video3&GeneralPhysicsII,Ch21-22-2.ElectrostaticforceandCoulomb’slaw(静电力与库仑2.ElectrostaticforceandCoulomb’slaw(静电力与库仑定律(I)Electrostaticforce(静电力)Tobetheelectricforces movingstationarycharges,(notGeneralPhysicsII,Ch21--(II)Coulomb’slaw(库仑定律(II)Coulomb’slaw(库仑定律GeneralPhysicsII,Ch21-22-ComparingthegravitationalandelectrostaticComparingthegravitationalandelectrostaticGeneralPhysicsII,Ch21-22-AcontradictiontoasimpleAcontradictiontoasimpleGeneralPhysicsII,Ch21-22-ComparingthegravitationalandelectrostaticGeneralPhysicsII,ChComparingthegravitationalandelectrostaticGeneralPhysicsII,Ch21-22-GravitationalElectrostaticNewton’slaw = Coulomb’sbetweenbetweenReverseproportionaltoReverseproportionaltoGravitational𝐺=6.67×10−11𝑁∙Electrostatick=8.99×109𝑁∙Conservativeforce！(保守力Conservativeforce！(保守力(III)Principleofsuperposition(III)Principleofsuperpositionforelectrostaticforce(叠加原理SystemwithmanyGeneralPhysicsII,Ch21--Example:electricchargesinExample:electricchargesinaGeneralPhysicsII,Ch21-22-GeneralPhysicsII,ChGeneralPhysicsII,Ch21-22-A.the+x-C.A.the+x-C.the+y-E.noneoftheB.the–x-D.the–y-GeneralPhysicsII,Ch21-22-Threepointchargeslieattheverticesofanequilateraltriangleasshown.Allthreechargeshavethesamemagnitude,butcharges#1and#2arepositive(+q)andcharge#3isnegative(–q).Thenetelectricforcethatcharges#2and#3exertoncharge#1isChargey SummaryofChapter•SummaryofChapter••PropertiesofElectricFindelectrostaticforcebetweenchargedobjectsbyCoulomb’slawComparingthegravitationalandelectrostaticforcebyCoulomb’slawHomeworkforChapter15•GeneralPhysicsII,Ch21-22-ChapterChapterElectrostaticElectrostaticfieldsgeneratedbycharged(II)Superpositionofelectrostaticfield(静电场的叠加原理ElectrostaticfieldsgeneratedbychargedobjectswithcontinuouschargeMotionofchargedparticlesinElectrostaticfields(带电粒子在静电场中的运动)：casesforapointchargeandadipoleAcoupleofAcoupleof“simple”GeneralPhysicsII,Ch21-22-ElectricFieldsorActiononaElectricFieldsorActiononaGeneralPhysicsII,Ch21-22-I)DefinitionofE-TheI)DefinitionofE-Theelectricfieldisavectorfield(矢量场DefinitionofE-GeneralPhysicsII,Ch21-22-II）Electricfield•II）Electricfield•Anelectricfieldlineisanimaginarylineorcurvewhosetangentatanypointisthedirectionoftheelectricfieldvectoratthatpoint.GeneralPhysicsII,Ch21-22-GeneralPhysicsII,GeneralPhysicsII,Ch21-22-+--++GeneralPhysicsII,+--++GeneralPhysicsII,Ch21-22-2.Electrostaticfieldsgeneratedbycharged2.ElectrostaticfieldsgeneratedbychargedGeneralPhysicsII,Ch21-22-(II)Superpositionprinciple(II)Superpositionprincipleofelectrostaticfield(静电场的叠加原理Electricfieldduetomorethan1pointGeneralPhysicsII,Ch21-22-++the+x-the–x++the+x-the–x-the+y-the–y-noneofthe+GeneralPhysicsII,Ch21-22-Positivechargeisuniformlydistributedaroundasemicircle.TheelectricfieldthatthischargeproducesatthecenterofcurvaturePisin 𝐸=𝐸+ 𝐸=𝐸++Ony-axis：𝐸 y1 Onx-𝑝=xDipolemoment𝑝=GeneralPhysicsII,Ch-Findtheelectricfieldatpositionsonthedipoleaxis3.Electricfieldsduetochargedobjectswithacontinuous3.ElectricfieldsduetochargedobjectswithacontinuouschargeExampleFieldofarodofWeintegrateExandEyseparatelyfrom–ato+ax>>a>>GeneralPhysicsII,Ch23-likeaninfinitelineofchargeJustlikeapoint3.Electricfieldsdue3.ElectricfieldsduetochargedobjectswithacontinuouschargeExample2:FieldofaringofGeneralPhysicsII,Ch21-22-Example3:ElectricExample3:ElectricfieldofadiscofGeneralPhysicsII,Ch23-4.Motionofchargedparticlesin4.MotionofchargedparticlesinElectrostaticfields(带电粒子在静电场中的运动I)AchargedparticleinanelectricGeneralPhysicsII,Ch21-22-II)Adipolei