复旦大学《大学物理》课件（英文）-第11章Work and kinetic energy(1).pdfVIP免费

Ch.11EnergyI:WorkandkineticenergyCh.11EnergyI:WorkandkineticenergyCh.11EnergyI:Workandkineticenergy11-1WorkandenergyExample:Ifapersonpullsanobjectuphill.Aftersometime,hebecomestiredandstops.WecananalyzetheforcesexertedinthisproblembasedonNewton’sLaws,butthoselawscannotexplain:whytheman’sabilitytoexertaforcetomoveforwardbecomesusedup.Forthisanalysis,wemustintroducethenewconceptsof“WorkandEnergy”.Ch.11EnergyI:WorkandkineticenergyNotes:1)The“physicsconceptofwork”isdifferentfromthe“workindailylife”;2)The“energy”ofasystemisameasureofitscapacitytodowork.Ch.11EnergyI:Workandkineticenergy11-2Workdonebyaconstantforce1.Definitionof‘Work’TheworkWdonebyac...