Chapter 9 Sound Waves Assignment PDF

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Chapter 9 Sound Waves Assignment...

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Chapter9SoundWavesAssignment Due:11:59pmonSaturday,March15,2014 Tounderstandhowpointsareawarded,readtheGradingPolicyforthisassignment.

Exercise16.5 PartA Whalecommunication.Bluewhalesapparentlycommunicatewitheachotherusingsoundoffrequency17.0 ,whichcanbeheardnearly1000 awayintheocean.Whatisthewavelengthofsuchasoundin seawater,wherethespeedofsoundis1531 ? ANSWER: =





PartB Dolphinclicks.Onetypeofsoundthatdolphinsemitisasharpclickofwavelength1.50 isthefrequencyofsuchclicks?

intheocean.What

ANSWER: =





PartC Dogwhistles.Onebrandofdogwhistlesclaimsafrequencyof25.0 ofthissound?

foritsproduct.Whatisthewavelength

ANSWER: =





PartD Bats.Whilebatsemitawidevarietyofsounds,onetypeemitspulsesofsoundhavingafrequencybetween 39.0 and78.0 .Whatistherangeofwavelengthsofthissound? ANSWER: =





PartE Sonograms.Ultrasoundisusedtoviewtheinteriorofthebody,muchasxraysareutilized.Forsharpimagery, thewavelengthofthesoundshouldbearoundonefourth(orless)thesizeoftheobjectstobeviewed. Approximatelywhatfrequencyofsoundisneededtoproduceaclearimageofatumorthatis1.00 acrossif thespeedofsoundinthetissueis1550 ?

ANSWER: =





Exercise16.17 Asoundwaveinairat

hasafrequencyof155

andadisplacementamplitudeof5.50×10−3

PartA Forthissoundwavecalculatethepressureamplitude(inPa). Use1.42×105

fortheadiabaticbulkmodulus.

ANSWER: =





PartB Findtheintensityofthewave. Use1.20

forthedensityofair.

ANSWER: =





PartC Findthesoundintensitylevel(indecibels). Use1.00×10−12

forthereferenceintensity.

ANSWER: 



Exercise16.26 Thefundamentalfrequencyofapipethatisopenatbothendsis579

PartA Howlongisthispipe?Use =344 ANSWER:

.

.

.

=





PartB Ifoneendisnowclosed,findthewavelengthofthenewfundamental. ANSWER: =





PartC Ifoneendisnowclosed,findthefrequencyofthenewfundamental. ANSWER: =





Exercise16.35 Twoloudspeakers, and ,aredrivenbythesameamplifierandemitsinusoidalwavesinphase.Thefrequencyof thewavesemittedbyeachspeakeris686 .Youarestandingbetweenthespeakers,alongthelineconnecting themandareatapointofconstructiveinterference.

PartA Howfarmustyouwalktowardspeaker tomovetoreachthefirstpointofdestructiveinterference? Takethespeedofsoundtobe344

.

ANSWER: =





Exercise16.41 Twoorganpipes,openatoneendbutclosedattheother,areeach1.11

long.Oneisnowlengthenedby3.00

PartA Findthefrequencyofthebeattheyproducewhenplayingtogetherintheirfundamental. ANSWER: =





.

Exercise16.47 Aswimmingduckpaddlesthewaterwithitsfeetoncepertimeintervalof1.4 ,producingsurfacewaveswiththis period.Theduckismovingatconstantspeedinapondwherethespeedofsurfacewavesis0.36 ,andthe crestsofthewavesaheadoftheduckhaveaspacingof0.20 .

PartA Whatistheduck'sspeed? Expressyouranswerusingtwosignificantfigures. ANSWER: =





PartB Howfarapartarethecrestsbehindtheduck? Expressyouranswerusingtwosignificantfigures. ANSWER: 



Exercise16.55 AjetplanefliesoverheadatMach1.72andataconstantaltitudeof956

.

PartA Whatistheangle oftheshockwavecone? ANSWER: =





PartB Howmuchtimeaftertheplanepassesdirectlyoverheaddoyouhearthesonicboom?Neglectthevariationof thespeedofsoundwithaltitude. Takethespeedofsoundtobe344 ANSWER: =

 

.

Exercise16.43 OntheplanetArrakisamaleornithoidisflyingtowardhismateataspeedof26.0 of1190 .

whilesingingatafrequency

PartA Ifthestationaryfemalehearsthesoundatafrequencyof1250 atmosphereofArrakis?

,whatisthespeedofsoundinthe

ANSWER: =





Exercise16.22 InOctober1991,theSacramentoCityCounciladoptedalawtoreducetheallowedsoundintensitylevelofthemuch despisedleafblowersfromtheircurrentlevelofabout95 to70 byMay1992.

PartA Withthenewlaw,whatistheratioofthenewallowedintensitytothepreviouslyallowedintensity? Expressyouranswerusingtwosignificantfigures. ANSWER:

Exercise16.18 Youliveonabusystreet,butasamusiclover,youwanttoreducethetrafficnoise.

PartA Ifyouinstallspecialsoundreflectingwindowsthatreducethesoundintensitylevelby35.0 haveyoureducedthesoundintensity?

,bywhatfactor

ANSWER: =

PartB If,instead,youreducetheintensitybyhalf,whatchange(in ANSWER:

)doyoumakeinthesoundintensitylevel?

=





Exercise16.38 Twosmallstereospeakersaredriveninstepbythesamevariablefrequencyoscillator.Theirsoundispickedupby amicrophonearrangedasshowninthefigure.Assumethatthespeedofsoundis 344 .

PartA Forwhatfrequenciesdoestheirsoundatthespeakersproduceconstructiveinterference? Expressyouranswerintermsofn(anintegerfactor). ANSWER: =





PartB Forwhatfrequenciesdoestheirsoundatthespeakersproducedestructiveinterference? Expressyouranswerintermsofn(apositiveintegerfactor). ANSWER: =





ScoreSummary: Yourscoreonthisassignmentis0.0%. Youreceived0outofapossibletotalof90points....