EnglishHomeworkforChapter1ancienttimestherectilinearpropagationoflightwasusedtomeasuretheheightofobjectsbycomparingthelengthoftheirshadowswiththelengthoftheshadowofanobjectofknownlength.Astaff2mlongwhenhelderectcastsashadowlong,whileabuilding’sshadowis170mlong.Howtallisthebuilding?Solution.Accordingtothelawofrectilinearpropagation,weget,x=100(m)Sothebuildingis100mtall.fromawatermediumwithn=isincidentuponawater-glassinterfaceatanangleof45o.Theglassindexis.Whatangledoesthelightmakewiththenormalintheglass?Solution.Accordingtothelawofrefraction,Weget,Sothelightmakewiththenormalintheglass.3.Agoldfishswims10cmfromthesideofasphericalbowlofwaterofradius20cm.Wheredoesthefishappeartobe?Doesitappearlargerorsmaller?Solution.Accordingtotheequation.andn’=1,n=,r=-20wecangetSothefishappearslarger.objectislocated2cmtotheleftofconvexendofaglassrodwhichhasaradiusofcurvatureof1cm.Theindexofrefractionoftheglassisn=.Findtheimagedistance.Solution.Refertothefigure.Accordingtotheequationandn=1,n’=,l1=-2cm,r1=1cm,wegetEnglishHomeworkforChapter2object1cmhighis30cminfrontofathinlenswithafocallengthof10cm.Whereistheimage?Verifyyouranswerbygraphicalconstructionoftheimage.Solution.AccordingtotheGauss’sequation,andl=-30cmf’=10cm.wegetOthersareomitted.lensisknowntohaveafocallengthof30cminair.Anobjectisplaced50cmtotheleftofthelens.Locatetheimageandcharacterizeit.Solution.AccordingtoGauss’sequation,andf′=30cml=-50cmwegetTheimageisareal,largerone.objectistransparentcube,4mmacross,placed60cminfrontof20cmfocallength.Calculatethetransverseandaxialmagnificationanddescribewhattheimagelookslike?Solution.FromGauss’sequation,wefindfortherearsurfaceofthecube(thefaceclosertothelens)that,Forthefrontsurface(thefacefartherawayfromthelens),ThetransversemagnificationfortherearsurfaceisButtheaxialmagnificationisSince,thecubedoesn’tlooklikeacube.biconvexlensismadeoutofglassofn=.