sat物理考試經(jīng)?？嫉脑~匯整理3篇

1/1sat物理考試經(jīng)常考的詞匯整理3篇sat物理考試經(jīng)?？嫉脑~匯整理1DeBrogliewavelength

Awavelength,givenby=h/mv,whichisassociatedwithmatter.LouisdeBroglieproposedtheideathatmattercouldbetreatedaswavesin1923andappliedthistheorysuccessfullytosmallparticleslikeelectrons.

Decayconstant

Aconstant,,nottobeconfusedwithwavelength,thatdefinesthespeedatwhicharadioactiveelementundergoesdecay.Thegreateris,thefastertheelementdecays.

Decibel

Alogorithmicunitformeasuringthevolumeofsound,whichisthesquareoftheamplitudeofsoundwaves.

Deposition

Theprocessbywhichagasturnsdirectlyintoasolidbecauseitcannotexistasaliquidatcertainpressures.

Destructiveinterference

Thecancellationofonewavebyanotherwavethatisexactlyoutofphasewiththefirst.Despitethedramaticnameofthisphenomenon,nothingis“destroyed”bythisinterference—thetwowavesemergeintactoncetheyhavepassedeachother.

Diffraction

Thebendingoflightatthecornersofobjectsorasitpassesthroughnarrowslitsorapertures.

Diffractiongrating

Asheet,film,orscreenwithapatternofequallyspacedslits.Typicallythewidthoftheslitsandspacebetweenthemischosentogenerateaparticulardiffractionpattern.

Direction

Thepropertyofavectorthatdistinguishesitfromascalar:whilescalarshaveonlyamagnitude,vectorshavebothamagnitudeandadirection.Whengraphingvectorsinthexycoordinatespace,directionisusuallygivenbytheanglemeasuredcounterclockwisefromthexaxistothevector.

Directlyproportional

Twoquantitiesaredirectlyproportionalifanincreaseinoneresultsinaproportionalincreaseintheother,andadecreaseinoneresultsinaproportionaldecreaseintheother.Inaformuladefiningacertainquantity,thosequantitiestowhichit'sdirectlyproportionalwillappearinthenumerator.

Dispersion

Theseparationofdifferentcolorlightviarefraction.

Displacement

Avectorquantity,commonlydenotedbythevectors,whichreflectsanobject’schangeinspatialposition.Thedisplacementvectorpointsfromtheobject’sstartingpositiontotheobject’scurrentpositioninspace.IfanobjectismovedfrompointAtopointBinspacealongpathAB,themagnitudeoftheobject’sdisplacementistheseparationofpointsAandB.NotethatthepathanobjecttakestogetfrompointAtopointBdoesnotfigurewhendeiningdisplacement.

Distance

Ascalarquantity.IfanobjectismovedfrompointAtopointBinspacealongpathAB,thedistancethattheobjecthastraveledisthelengthofthepathAB.Distanceistobecontrastedwithdisplacement,whichissim*ameasureofthedistancebetweenpointsAandB,anddoesn’ttakeintoaccountthepathfollowedbetweenAandB.

Dopplershift

Wavesproducedbyasourcethatismovingwithrespecttotheobserverwillseemtohaveahigherfrequencyandsmallerwavelengthifthemotionistowardstheobserver,andalowerfrequencyandlongerwavelengthifthemotionisawayfromtheobserver.Thespeedofthewavesisindependentofthemotionofthesource.

Dotproduct

Aformofvectormultiplication,wheretwovectorsaremultipliedtoproduceascalar.Thedotproductoftwovectors,AandB,isexpressedbytheequationA·B=ABcos.

sat物理考試經(jīng)常考的詞匯整理2Efficiency

Foraheatengine,theratioofworkdonebytheenginetoheatintake.Efficiencyisnever100%.

Elasticcollision

Acollisioninwhichbothkineticenergyandmomentumareconserved.

Electricgenerator

Adevicethatconvertsmechanicalenergytoelectricalenergybyrotatingacoilinamagneticfield;sometimescalleda“dynamo.”

Electromagneticinduction

Thepropertybywhichachargemovinginamagneticfieldcreatesanelectricfield.

Electromagneticspectrum

Thespectrumcontainingallthedifferentkindsofelectromagneticwaves,ranginginwavelengthandfrequency.

Electromagneticwave

Atransversetravelingwavecreatedbytheoscillationsofanelectricfieldandamagneticfield.Electromagneticwavestravelatthespeedoflight,m/s.Examplesincludemicrowaves,Xrays,andvisiblelight.

Electron

Anegativelychargedparticlethatorbitsthenucleusoftheatom.

Electronvolt

Aunitofmeasurementforenergyonatomiclevels.1eV=J.

Energy

Aconservedscalarquantityassociatedwiththestateorconditionofanobjectorsystemofobjects.Wecanroughlydefineenergyasthecapacityforanobjectorsystemtodowork.Therearemanydifferenttypesofenergy,suchaskineticenergy,potentialenergy,thermalenergy,