教程sat2物理精华

ThevelocityofawaveonastringisgivenbythevwhereTisthetensioninthestring isthelinearmassdensityoftheAveragevelocityisameasureoftotaldiscementovertotal4lawsofZerothIfsystemAisatthermalequilibriumwithsystemB,andBisatthermalequilibriumwithsystemC,thenAisatthermalequilibriumwithC.FirstConsideranisolatedsystem—thatis,onewhereheatandenergyneitherenternorleavethesystem.TheFirstLawisjustanotherwayofstatingthelawofconservationofenergy.TheSecondLawPerhapsthemostintuitiveformulationoftheSecondLawisthatheatflowsspontaneouslyfromahotterobjecttoacolderone,butnotintheoppositedirection.1Heat2nomachinecanworkat100%3orderedsystemsareliabletofallintodisorder,butdisorderedsystemsarenotliabletoorderthemselvesspontaneously.4.timemovesinthedirectionofentropyThirdItisimpossibletocoolasubstancetoabsoluteTheequationforthegravitationalpotentialenergyofanetinorbitisAngularmomentuml=Iw=mvrmomentofinertiaofI=Atveryshortdistances,thestrongnuclear pullsprotonsandneutronstogetherwithamuch thantherepulsionbetweenlikechargesexercisedbytheelectromagnetic Becauseofthestrongnuclear ,anucleushasasmallermassthanthesumofthemassesoftheindividualprotonsandneutronsthatmakeitup.Thisdiscrepancy,ormassdefect,istheamountofmatterthatisconvertedintoenergywhenthenucleusisformed,accordingtoEinstein’sprincipleofmass-energyequivalence.Theamplitudeofthesoundwaveisrelatedtohowloudthesoundis,andthisisaffectedbythemediumthroughwhichittravelsConvectionisatypeofmotionfoundinagasorliquidwherethereisatemperaturedifferencebetweentheregionsWhenmakingameasurementthatinvolvesseveraldifferentties,theresultingmeasurementcanonlybeaccuratetothenumberofsignificantdigitsofthetythathasthesmallestnumberofsignificantdigits.IftheEarthwereofperfectlyuniformcomposition,duringadescenttothecentreoftheEarth,gravitywoulddecreaselinearlywithdistance,reachingzeroatthecentre.Heatcanflowbyconduction,convection,orradiation传导,对流,angularmomentum,L=Adielectricincreasesthecapacitancesinusoidalwave正弦曲线Tungstenfilamentisjustafancywayofsayingtungsten,whichhasthechemicalsymbolNewton’sFirstLawdescribeshowsrelatetoAnobjectatrestremainsatrest,unlessacteduponbyanet.Anobjectinmotionremainsinmotion,unlessacteduponbyanet.Toeveryaction,thereisanequalandoppositeTheelectricpotentialofachargeisgivenbytheequationV=thepotentialenergyofachargedecreasesasworkisdoneon V=El=yanksolenoidApositivelyornegativelychargedionisstillanatom,eventhoughtherearemoreorfewerelectronsthanthereareprotons.TheThenumberofprotonsinanatomplusthenumberofneutronsinthatatomgivesthenumberofthatWhenawavepulsehitsawall,itwillbouncebackinverted.Thewavelengthofthewavedependsonthelinearmassdensityandtensionofthestring,neitherofwhichareaffectedbythewavebouncingoffthewall,sothewavelengthwillremainconstant.Whenreportingameasurement,thelastdigitisalwaysuncertain,andcanbeoffbyasmuchasone-halfthevalueofthesecondtolastdigit.2.16 voppositecurrentsrepeloneItturnsoutthatthereisalinearrelationshipbetweenthevalueofgandthevalueofRbetweenthesurfaceoftheEarthandthecenteroftheEarth,Insertingadielectricintoacapacitorreducestheelectricfieldbetweenthetes.Theelectronsinthedielectricareattractedtothepositivete,andcreatetheirownelectricfieldinthedielectric.Thisfieldopposestheoriginalfieldinthecapacitor,andtheoverallelectricfieldisreduced.Sincepotentialdifferenceisdirectlyproportionaltothestrengthoftheelectricfield,italsodecreases.Convectionisatypeofmotionfoundinagasorliquidwherethereisatemperaturedifferencebetweentheregions.AnexchangeofheatbetweenwarmerandcoolerregionsinagasorCenterofTheequationforthegravitationalpotentialenergyofanetinorbitAuroraBorealis北V1/V2=N1/N2transofrmerreverse颠倒retardation延迟Continuous连续的Linespectra发射光谱Polarimeter偏振器 willbeweightlessatthecenteroftheearthbecauser=0,andallthemassoftheearthisattractingthe fromoutsidethecenter ysisisexac