Conservation of Energy Lab - Montgomery County Public Schools能源实验室保存的蒙哥马利县公立学校

ConservationofEnergyLabName_____________________Pd______LabPartners:_______________________________________________________________Purpose:Inthisexperiment,thelawofconservationofenergywillbeinvestigatedbycomparingthestartingpotentialenergyofapendulumtoitskineticenergyasitswingsthroughitslowest(equilibriumposition)point.TestableQuestion:Doesthekineticenergyofapendulumatthebottomofitsswingequalthechangeinitspotentialenergyfromitsdropposition?Materials:1200gstandardmass1meterstick2C-clamps1lengthofstringatleast0.5mlongapprox.8meteroftickertapemaskingtape1meterstickringstandProcedure:Measurethemassofapendulumbobandrecordinthedatachart.Assumethatthespacebetweenanytwotickertapedotstakes1/60thofasecondtocreateAttachtheendofthetapetothependulumbob,asshownintheillustration.CarbondiskCarbondisk200gmassTickertapeWithNOSLACKRingstandTickertimerMeasuretheheightthatthependulumbobisabovethetable(notabovetheringstandbase)whenthependulumisinitsverticalequilibriumposition.DisplacethependulumtoonesideuntiltheverticaldistancebetweenthependulumandthetableishigherthanitwasattheequilibriumpositionMeasurethependulumbob’snewheightabovethetabletop,startthetimerandreleasethependulum.Whenthependulumhasswungovertotheothersideandisjuststartingbackdown,stopthependulumandthetickertimerandexaminethetape.Findthelargestspaceonthetapeandmeasureit.Convertthedistancemeasurementtometersandcalculatethemaximumspeedthatthependulumachievedduringitsswingbydividingthedistancebythetimethatisassociatedwithasingleintervalonthepaper(time/space=1/60thsecond).KE=½mv2KE=½mv2 Repeattheaboveprocedure,raisingthependulumbobtofourotherdifferentheights.Calculatethepotentialenergyofthebobbeforeitstarteditsswingbyusing:ComparetheinitialPEforeachswingtothefinalmaximumKEforeachswingbycalculatingthe%differenceforeachtrial,usingthePEasthetruerofthetwovalues.SuggestionsandTechniques:Useapendulumthatisatleast0.5meterlong.Whenmeasuringthedistancebetweenthependulum(thebob)andthetopofthetable,youmaymeasuretoanypartofthependulumbob,aslongasthesamepartofthebobisusedforeachmeasurement.Data:Massofpendulumbob_________grams__________kilogramsRestheightofbobabovetable:________cmTrialheightofdropfromtable(cm)h(cm)h(m)PE(J)dmax(cm)dmax(m)t(sec)vmaximum(m/s)KE(J)%diff.ofPEandKE11/602345678Ave%Differ.SampleCalculations:QuantityFormulaSubstitutionAnswerw/UnitsgtokgcmtomhPEMaximumvelocityKE%difference(PE-KE)100PEQuestions:1.WhenyoucomparetheaveragevaluesofyourPEstothevalueoftheKEsforeachswing,whattrend/sdoyounotice?2.Whatfactor/smightaccountforthetrend/syounoticedin#1above?3.Onaseparatesheetofpaper,explainwhichkindofenergy(PEorKE)thatONEofthosefactorswouldaffectandhowitwouldaffectthatenergy.(Youmayuselabeleddiagrams,explanations,oracalculationtoshowthis)4.Howcloselydidyourchangeinpotentialenergymatchyourmaximumkineticenergy?Justifyyouranswer5.Overall,areyouconvincedthatthelawofconserv