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Physics4150Optics,Fall2017,M.Goldman,D.Newman

HW-4(totalvalue=40pts)dueTues.Oct10,inclass

1. Refraction(10pts)a) Doesthewomanseethemanstandinginthewateruptohischestasshorter,tallerorthesameheightashereallyis.Explainqualitativelyusingwordsandraytracingfromthexontheman'sfintohereye.(8pts)

b) Whatdoesthechildsnorkelerwitheyesverynearthesurfaceofthewaterseewhenhelooksupinthedirectionshown?Explainusingwordsandraytracingonthepictureabove(7pts).

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2. (14)Alex'simageis4cmfromalenswhileheis12cmfromthelens.onthesamesideashisimage.Usetheappropriateformulasandshowallworkinansweringthefollowingquestions:

a)Whatisthefocallengthofthelensandisitaconvexoraconcavelens?(6pts)b)Whatisthemagnification?IshisimagelargerorsmallerthanAlex?(4pts)c)Isitrealorvirtual?Upsidedownorrightsideup?(2pts)d)CanAlexseehisownimagefromwhereheis?Why?(2pts)

3. (10pts)Thinconvexlens2isadistanced12totherightofthinconvexlens1alongthesameaxis.Togethertheyformanon-touchingcompoundlens.Inclassthelenseqnwasappliedtoasimilarcompoundlensusingtheconceptofanintermediate-image/effective-object.Thefinalimagewasreal.

Underwhat(ifany)conditionsisthefinalimagevirtual.Forwhatrangeofobjectdistancesfromlens1,x0Lens1isthefinalimagevirtual?Giveyouranswerintermsofthefocallengthsf1,andf2,withalldistancesinunitsofd12.

4. (6pts)Fishwhichspendasignificantportionoftheirdaysnearthesurfaceofthewatercanactuallyseewhat'sgoingonabovethesurface.Therefractionoflightgivesthemafieldofvisionthatencompasses180°onthesurfaceeveniftheirunder-waterfieldofvisionissmaller.What field of vision for a fish underwater corresponds to a 180° field of vision above the surface?