Ma ny o f the des ig nat io ns use d by ma nufac tur ers a nd se ll ers to di stin g ui s h th eir pro du c ts are cla im eil as tra dema rk s. Wh e re th ose des ig na tio ns appea r in thi s book, a nd the p ubl is her was aware of a trade ma rk claim , the des ig na ti o ns have bee n pr in ted in initi a l caps or a ll caps.
Mas ter in g Ph ys ies a nd Ac t iv Ph ysies are tra demarks, in t he U.S. a ndlor o th e r co un tries, o f Pearso n Educat io n , In c. or it s a ffili ates.
MeAT is a regis tere d tra demark of the Assoc ia t io n of Ame ri ca n Med ical Co lleges. MeAT exa m materia l in c lud ed is pr inted w ith th e pe rmi ssio n o f th e AA MC. T he AA M C docs no t e nd orse thi s bo o k
Library of Congress Cat al oging- in -P ublication Data
K nig h t. Ra nda ll Dewey. College phys ics: a s t rategic approac h I Ra nd a ll D Kni g ht. Bria n Jo nes, S tua rt Fiel d - 2 nd ed p. cm.
In c ludes bib liog rap hi cal refe re nces a nd ind ex. IS BN
l. Physics - Tex tb ooks. I. J o nes , Bria n II . Fie ld , S tu a rt. HI. Ti t le. QC23.2 .K 64920 10 530-----<.l e22
1 2 3 4 5 6 7 8 9 I()-{: RK - 13 12 " 1009
Addison -Wesley i s a n imprin t o f
About the Authors
Randy Knight ha s taught introductory physics for 28 years at Ohio State University and California Pol ytec hni c University, where h e is c urr e ntly Professor of Ph ysics and Director of the Minor in Environmental Studies . Randy received a Ph.D. in physics from the University of California, Berkeley and was a po st- do cto ral fellow at th e Har va rd -S mith so nian Center for Astrophysics before joining the faculty at Ohio State University. It was at Ohio th a t he bega n to learn about th e re sea rch in physics e ducation that, man y years later, led to Five Easy Lessolls: StraTegies for Successful Physics Teaching, Physics for Scientists alld En gineers: A Strategic Approach, and now to thi s book. Rand y's research interests are in the field of lase r s and spec tro scopy. He also directs the environmental studie s program at CaJ Poly. Wh e n he's nOl in the c la ssroo m or in front of a computer, yo u can find Rand y hiking , sea kayaking, playin g th e piano, or spe nding time with hi s wife Sall y and their s ix cats.
Brian Jones ha s won seve ral teach in g awards at Colorado State University during hi s 20 years teaching in the D e partment of Physics. Hi s teaching fo c u s in rece nt years ha s been th e CoLlege Physics class, including writing problems for the MCAT exa m and he lpin g st udent s review for this test. Brian is also Direc tor of th e LillIe Shop of Physics, the Department's e ngagi ng and effective hand s-on outreach program, which ha s m e rit ed coverage in publication s ranging from the APS News to People magazine. Brian ha s been invited to give workshops on technique s of sc ie nce instruction throughout the United States and internationall y, including Belize, ChiJe, Ethiopia, Azerbaijan , Mexico and Slovenia. Previo u s ly, h e tau g ht at Wat e rford Kamhlaba United World College in Mbabane, Swaziland, and Kenyo n College in Gambier, Ohio. Brian and hi s wife Carol hav e dozens of fruit trees and bu s hes in th eir yard, includin g an apple tree that was propagated from a tree in Isaac Newton's garden , and they hav e traveled and ca mp ed in most of th e United States.
Stuart Field ha s been int e res ted in science and technology hi s whole life. Whil e in sc hool he built tel escopes, e lec troni c circuits, and computers. After attending Stanford University, he earned a Ph.D. at the University of Chicago, where he s tudi ed the properties of mat e ri a l s at ultralow t e mperatures. After co mpletin g a postdoctoral pos ition at the Ma ssac hu setts In st itute of Tec hn o logy, h e h e ld a faculty po s iti o n at the University of Michigan. Currently at Colorado State University, Stuart teaches a variety of ph ysics courses, including algebra-based introductory physics, and was an ea rly and enthusiastic adopter o f Knight's Physics for Scielllists Wid Engineers. Stuart maintain s an active researc h pro g ram in th e area of s uper co ndu c tivit y. Hi s hobbi es include woodworking; enjoyi n g Colorado's great outdoors; and ice hocke y, where he plays goa li e for a local team.
Preface to the Instructor
FIVE EASY LE S SO N S
Strategies for Successful Physics T l:3C hing
RANDALL D KNIGHT
In 2 0 0 6 , we publi s he d Col/ege Physics: A Slraleg ic Approach, a new a lge br a-base d ph ys ic s t ex tb ook fo r st ud e nt s m ajorin g in th e bi o logic aJ a nd life sc iences, ar c hit ectur e, na tural reso ur ces, a nd o th e r di sc iplin es. As th e fir st s u c h bo o k built from th e g round up o n resea r c h into how s tud e nt s ca n m o re e ffe c ti ve ly le a rn ph ys ics, it qui ckl y g ain ed wid es prea d c riti ca l ac cl a im f ro m p rofesso r s a nd s tud e nt s a like. In thi s seco nd e dition , w e build o n th e rese arc h- p rov en in s tru ct io nal te chniqu es introdu ce d in th e fir st e dition and th e ex t e ns ive feedb ac k from th o u sa nd s o f u se r s to take stud e nt le arnin g eve n f urth e r.
Objectives
Our primar y goa ls in w ritin g Co ll ege Ph ysics: A S tra tegic A pproac h ha ve bee n :
• To p ro vid e st udent s w ith a t ex tb oo k that 's a m o re man age abl e s ize, less e ncyc lope di c in it s cove ra ge and be tt e r des ig ne d fo r lea rnin g.
• To integ rat e pro ven techn.iqu es from ph ys ics e du c ati o n resea rc h int o th e c lassro o m in a way that acco mmodates a ran ge o f teac hin g an d le arn i ng s ty les.
• To he lp stud e nt s d ev el o p bo th qu a ntit a ti ve reaso nin g s kill s and so lid co nce ptu a l und e rs tandin g, w ith s pec ial foc u s o n c on c epts we ll do c um e nt e d t o c au se le a rnin g di ffi c ulti es.
• To he lp s tud e nt s d eve lo p p ro bl e m- so lv in g s kill s a nd co nfid e nce in a sys t e m a ti c ma nn e r u s i ng ex pli c it a nd co ns i st e nt t ac ti cs and strat eg ie s
• To m o ti v at e s tud e nt s b y int eg ratin g rea l - wo rld ex ampl es re l eva nt to th e ir m aj o rs-es p e ciall y f ro m bi o logy, s p o rt s, m e di c in e, th e anim a l w o rld-a nd th a t build upon th e ir every d ay ex pe ri e nces
• To utili ze prove n tec hniqu es o f v is ua l in s tru c ti o n and d es ig n from e du c ati o nal rese ar c h a nd cog niti ve p syc h o logy th a t imp rove stud e nt lea rnin g a nd re t e nti o n and address a ran ge o f le arn e r s ty les.
A mo re co mpl e te ex pl a nati o n o f th ese goa l s a nd th e rati o n a le be hind th e m ca n be fo und in Rand y Kni g ht 's pape rba c k boo k , Fi ve Easy Lessons: Strateg ies for S u ccessful Phys ics Tea c h in g. Pl e a se re qu es t a co py from yo ur local Pea r so n sa les re prese ntati ve if it wo uld b e o f int e res t to yo u (I SB N 978- 0 -805-387 02 -5)
What's New to This Edition
Our goa l from th e beg innin g h as bee n a t ex tb ook co mbinin g th e bes t res ult s from ph ysic s e du c ati o n resea rc h w it h in s pirin g ph o tog rap h s and exa mpl es co nn ec tin g ph ys ics to th e m a ny fi e ld s of st ud y o f stud e nt s takin g Co ll ege Ph ys ics. In o th e r wo rd s, to pro v ide both th e mo ti va ti o n need e d and th e to o ls re quir e d for stud e nt s to su cceed Ou r commitment to thi s goa l i s undimini s he d. A t th e sam e tim e, th e ex t e ns i ve fee db ac k we ' ve rece i ve d fro m sco res o f in stru c t o r s a nd hundre d s o f s tud e nts, a s we ll a s o ur o w n ex pe rien ces t eac hin g from th e book, have le d to num e rou s c han ges a nd impro ve me nt s to th e tex t, fi g ures, a nd th e e nd -of-c hap te r probl e m s Th ese in cl ud e:
• N e w illu s trat e d Chapte r Previews a t th e s tart of e ac h c ha pt e r pro v id e v is u a l , hi e rar c hi c al , a nd no n-t ec hni cal prev iews p rov en t o h e lp stud e nt s o rg ani ze th e ir
thinkin g a nd impro ve th e ir und e r st a ndin g of th e up co min g mat e ri a l
• Ne w lntegrated Examples a t th e e nd o f e a c h c hapt e r g i ve s tud e nt s a dditi o na l
he lp in so lv in g ge ne ral probl e m s no t tied to parti c ul a r sec ti o n s. Man y integ rat e mat e ri a l f ro m o th e r c hapte rs.
c• New Part Summary Problems at th e e nd of eac h o f the seve n part s of the book t es t stud en t s' abi.litie s to draw on concep t s and tec hniqu es from multiple c h ap te r s. Mo s t of the se are MCAT-s tyl c pass ag e problem s .
• More streamlined presentations throughout th e text. Ba sed on ex ten s ive feedback, we 've pared s ome topic s, reco nfi g ured o th e rs, and provided a more readabl e, stud e nt - fri e ndl y text.
• Improv e d and more varied end-of-chapter probl e ms. Us in g data from Ma s teringPhy s ics, we have r eworke d the problem se ts to enhance c larit y, topi c cove ra ge, and va ri et y-add in g, in parti c ul a r, mo rc problems ba sed o n re al-world s ituati o ns and mor c problem s u s in g rati o rea so nin g.
Your In structor's Profe ss ional Copy conta in s a 9 - page illu s trat e d overv iew of the pe dagogical fe ature s in thi s sec ond e dition. The more s ig nificant co nt e nt changes includ e:
• The trea tm en t of Newto n 's third law in C h ap ter s 4 a nd 5 h as been better focu sed o n th e types of problem s that s tud e nt s w ill be a sked to so l ve.
• A ng ular pos iti o n and angular ve loc it y a re now d eve lo p ed t oget h er in Chapter 6, r a th e r th e n being divided b e tw ee n C h ap t e r s 3 and 6. More e mph asis has been give n to angular po s iti o n a nd a n g ul ar ve loc it y g raph s, e mpha s izing th e analogy w ith the lin ea r pos iti o n and ve loc it y graph s of C hapt e r 2.
• The Chapter 10 pre se ntation of work an d energy ha s been streamlined a nd c larifi e d. The problem -so l v in g strategy for conserva ti on of e nergy problem s now play s a more prominent role
• Chapter 11, Us in g Energy, i s now more f ocused o n co ncrete a ppli ca tion s of energy use. All di sc u ss ion s of thermal prope rtie s h ave m atter have bee n mo ved to C hapt e r 12, w hi c h ha s been reo rga ni ze d to e mpha s ize the s in g le th e m e, " What ha pp ens to matter w hen you he a t o r coo l it ?"
• Th e o rd er in g of topic s within Chapte rs 18 and 19 ha s been r ev i se d. Ra y tra c ing and th e thin - le n s eq uati o n ar e now paire d toget h e r in Chapt e r 18; the pinh o le camera a nd co lor/d is pers io n have moved to Chapter 19.
• Chapte r 2 1 ha s bee n s ig nificant ly rewritten to m ake th e diffi c ult idea of e lectric pote ntial more co nc re te and u sa bl e.
• The sec ti o n on ho u se hold electricity has been moved from Chapter 23 to C hapter 26. C hapt e r 23 i s now better fo c u sed o n resistors and capacitors while Chapter 26, AC C irc uit s, h as b eco me a m ore practical c h apte r w ith section s o n h o u se h o ld electricity and e le c tri cal safety.
• Chapter s 28-30 o n quantum , atomic , and nucl e ar phy s ic s h ave b een s ig nifi ca ntl y s tr e amlin e d in th e ho pe that more in structor s w ill b e abl e to teach th ese important topi cs .
Textbook Organization
College Physic s: A S trat egic Approach is a 30-c hapt e r t ex t intended for u se in a twose mes ter co ur se. The t ex tbo ok i s di v id ed into seve n part s: Part I : Force and Motion , Part II : Conservation Law s, Part III : Prop ert ie s of Maffer , Part IV: Oscillations a!ld Wa ves, Part V: Optics , Part VI: Ele c tricit y and Magneti s m , a nd Part VB : Mod e m Ph ys i cs.
Part I covers New to n 's la ws and th e ir appLica ti ons. The coverage of two fundamental conserved quantiti es, mom e ntum and e ne rgy , is in Pall ll , fo r two reaso n s. First , th e way that problem s are so lved us in g co nse rvation la ws----<::o mp a rin g an after s itu a ti o n to a before s ituati o n--differs f und a me ntall y from the problem- so l vin g s trategie s u sed in N ew tonian d y namics. S eco nd , th e co nce pt of e ne rgy h as a sig nifi ca nce far beyo nd mec hani c al (kin e tic and potential ) e ne rg ies. In pmti c ular, th e key id ea in th e rm odynamic s is e ne rgy, and m oving f rom th e study of energy in Part II into thermal phy s ic s in Part ill a ll ows th e unint e rrupt e d d eve lop me nt of thi s important ide a.
• Complete edition , w ith MasteringPhysics'M(ISBN 978-0-321S9S48-S):C hapters 1-30
• Volume 1 wi th MasteringPhysics ™ IIS B N 978-0 -3 21-59850-9) : Chapters 1- 16.
Optic s (Part V ) is co ve red dir ec tly after oscillations and waves (Part IV) , but before electricity and magneti s m (Part VI). Further, we treat wave optics before ray optics. Our motivation s for thi s organization are twofold. Firs t , wave optics is large ly ju st an exten s ion of the ge ne ral idea s of waves; in a more traditional organization, student s wiLl have forgotten much of what they learned about wa ves by the tim e th ey get to wave optics. Seco nd , optics a s it is prese nt e d in introductory phy s ic s make s no use of th e propertie s of electromagnetic field s. Th e documented difficultie s that s tudent s hav e with optic s are difficultie s with wave s, not difficultie s with e lec tricity and magn e ti s m. Th e re's littl e re a s on other than hi s tori c al tradition to delay optics. However, th e optics chapters ar e easily deferred until after Part VI for in structor s who prefer that orderin g of topic s.
The Student Workbook
A key component of College Ph ysics : A Strategic Approa c h is th e accompanyin g Student Wo rkb ook, The workbook brid g e s the gap between textbook and homework probl e m s by providin g stud e nt s th e opportunity to le arn and practic e s kill s prior to us ing tho se s kiU s in quantitative e nd-of-chapt e r problem s, much as a mu s ician practic es technique se parate ly from performan ce pieces. The workbook exercises, whi c h are ke ye d to eac h section of th e tex tbook , focu s on dev e loping s pec ifi c skill s, ranging from id e ntifying force s and drawing free-body diagram s to interpretin g field dia gra ms. The workbook exerc is e s, whjcb are generally qualitative and/or graphica l, draw he avily upon the ph ys ic s education resear c h lit e ratur e. Th e exercises d eal with iss ue s known to cause s tudent difficultie s and emp loy technique s that have proven to be effective at ov e rc oming tho se difficultie s . The workbook exercises can be u se d in -class a s parl of an activ e -l earning te aching s trat egy, in rec itation sec tion s, or as assigned hom ewo rk. Mo re information about e ffecti ve use of th e Studellt Workbook can be found in th e In structor's Guide Availabl e ve r s ion s: Volum e I ( ISBN 978-0-321-59632-1): Chapte r s 1- 16 , and Volum e 2 (ISBN 978-0-321-596 33-8): Chapters 17 -3 0, A packag e of bo th volumes is a lso available (ISBN 978-0-321-59607-9),
Instructor Supplements
Il!I!IDI For convenience, a ll of th e following in s tru c tor s upplement s (except for th e In s tru c tor Re so urc e DVD) can be downloaded from th e " In s tructor Area," accessed v ia th e left- hand navigation bar of Ma s te ringPh ys ic s ( www.maste ringphy s ic s.co m) . ...
• The Instructor Guide for College Physics: A Strategic Approach, a co mprehen s ive and highly acclaim e d re so urce , provide s chapter-by-chapter creative idea s and teachin g tip s for using College Ph ysics: A Strategic Approach in your cla ss . In addjtion, it contains an extensive rev iew of what ha s bee n le arn e d from phy s ic s edu c ation resea rch , and provid es guidebne s for us ing active-Iearn,ing te c hnique s in your classroom. In structor Guid e chapters are provid ed in Word and PDF format s, and are al so found on th e Instru ct o r Reso urce DVD.
• The Instructor Solutions Manual, writt e n by Profe sso r Larry Smith , Snow College; Professo r Pawan Kahol , Mi sso uri State Univers it y; and Professo r Marilin Simon, Auburn University, provid es complete so lution s to all the c nd -of-c hapter qu es tion s and problem s, All so luti ons fol -
low th e Prepare/ Sol vel A ssess problem- so l vi ng s trat egy used in the textbook for quantitative problem s, and Reaso n/ A ssess s trat egy for quaEtati ve ones. Th e so lution s are available by chapte r in Word and PDF format , and can al so be downloaded from the Instru c /or Reso urc e Center ( www .pe ar so nhi g he re d .com /e du c awr ) .
• Th e cross-platform Instructor Resource DVD (ISBN 978-0-32l-59628-4 ) provide s invaluable and easy -to-u se reso urc es for yo ur class, organized by tex tbook chapter. The contents include a compre hen s ive library of more than 220 applets from ActivPhysics OnLine " ', as well as all fi g ure s, photo s, tabl es, and s ummarie s from th e tex tbook in JPEG format In addition, all the Problem-Solvin g Strategi es, Math Relation s hip s Boxes, Tacti cs Boxes, and Key Equations are provided in editable Word as well a s JPEG format Th e Instructor Guide is al so includ e d a s editable Word file s , along with pdfs of an s wer s to the Student Workbook exe rc ises, and Lecture Outlines (wit h Classroom Response System "Clicker" Questions) in PowerPoint.
c• lMP t'
MasteringPhysics™ ( www.masteringphysics.com ) is a homework, tutorial, and assessment sys tem d es ign e d to assign , assess, and tra ck eac h stud e nt 's progre ss u s ing a wide diver s it y of tutorials and ex te ns iv e ly pre-te s ted problem s. Tn addition to th e textbook' s end-ofc hapt e r and new e nd -of- part probl e ms, Ma ste ringPhy s ic s for College Ph ysics Second Edili oll, also includ es authorse lec ted prebuilt assignments, s pecific tutorial s for aU the textbook 's Probl e m- Solvin g Strategies, Tactics Box es, and Ma t h Relation s hip box es, as well a s Re ading Qui zzes and Te st Bank questions for each c hapter.
Ma s te rin g Phy s ics pro v id es in s tru c tor s with a fa s t and effec tive way to assign uncompromi s ing , wide-ranging online homework assignments of ju st the right diffi c ult y and duration. Th e tutorial s coach 90% o f s tud e nt s to th e correct answer with s pec ific wrong-an swe r feedback. Th e powerful po st-a ss ig nm e nt diagnostics allow in structor s to assess the pro g ress of their class as a whole or to quickly identify individual student 's areas of di.ffi c ulty.
• Act \ ' v ActivPhysics OnLine'" (accessed through the Self Phys cs Study ar ea within www.masteringphysics com ) provid es a comprehensive librar y of more than 420 tried and te s ted AcrivPhysics applets updated for web delivery
Student Supplements
• Th e Student Solutions Manuals Chapters 1-16 ( ISBN 978-0-321-59629-1) and Chapters 17-30 (ISBN 978-0321-59630-7), written by Professor Larry Smith , Snow CoLlege ; Professo r Pawan Kahol , Mi sso uri State Univers ity ; and Marilin Simon, Auburn University, provide derailed so lution s to mor e than half of the odd-numbered e nd-of-c hapt e r problems. Following th e probl e m-so l v ing strat egy presented in th e text , thorough so lution s are provided to ca refully illu s trat e both th e qualitative ( Reaso nl Assess) and quantitati ve (pre parelSo l vel Assess) step s in th e probl e m- so lvin g pro cess. • lMP {" MasteringPhysicsn, ( www mas te rin g phy sics.com ) is a hom ewo rk , tutorial, and assessment syste m ba sed on ye ar s of re searc h into how s tudent s work phy s ics problem s and prec ise ly where they need help. Studies s how that stud e nt s who use Ma st e ringPh ys ics s ignificantly increase their finaJ sco re s compared to hand-written homework. Ma sterin gP hys ics achieves this impro ve ment by prov iding st ud e nt s with in s tantan eo u s feedback s p ec ific to their wrong answers, s impler s ub-probl e m s upon re que st when th ey get s tu c k, and partial credit for th ei r me thode s) u sed. Thi s indi v iduaLi ze d , 2417 Socratic tutoring is reco mmended b y nin e out of ten student s to their pee rs as the mo st effective and time -effic ie nt way to study.
• Pearson eText is available throu g h MasteringPhysics, e ith e r automatically when MasteringPhysics is package d with new books, or available as a purc hased up g rad e online. AJJowing s tud e nt s ac cess to the tex t wherever th ey hav e
Preface to the Instructor vii
u s ing the late st online technolo g ies. In addition , it provides a suite of highl y rega rded applet-based tutorial s developed b y e ducati o n pion ee rs Professo rs Alan Van He u ve le n and PaulO' Alessandris. Th e AcrivPhysics margin icon directs s tudent s to s pecific exercises that co mplement the te x tbook discussion.
Th e online exe rci ses ar e de s ign e d to encourage s tudents to co nfront mi sco nc e ption s, rea so n qualitatively about phy s ical processes, ex pe riment quantitativ e ly, and lea rn to think critically. The y cove r all topic s from mec hanics to electricity and magneti s m and from optics to mod e rn phy s ics . The hi g hl y acclaim e d AcrivPhysics OnLille co mpanion workbooks he lp s tud e nt s work through complex concepts and und e rstand them more clearly. More than 220 applets from th e AcrivPhysics OnLine Library are also available on th e Ill structor Resource DVD.
• The Test Bank , prepared by Wa y ne Anderson, co ntain s more than 2,000 hi g h-quality problems, with a range of multipl ec ho ice , tru e/fa lse, s hort-an swe r, and reg ular ho mework-t y pe questions. Tes t file s are provided in both Te stGen ® (a n easyto -use, fuLl y ne tworkable program for c reatin g and e ditin g qui zzes and exams) and Word fonnat , and can a lso be downJoaded from www pearsonhighered.comJeducator
access to th e Int e rnet , Pearso n e Tex t comprises th e fuLl text , includin g figure s that ca n be e nlarg e d for b e tter v iewing Within eText, st udent s are also abl e to pop up d e finition s and te rm s to he lp with vocabulary and th e rea ding of th e material. Students can also tak e notes in eText u s ing th e annotation feature at th e top of eac h pa ge .
Each s tud e nt' s s ub sc ripti o n to Ma st e rin g Ph ys ics also contain s co mplimentar y access to Pear so n Tutor Service s, pow e re d by Smarthinkin g , In c. By lo gg in g in with their Ma s te rin g Phy s ic s [0 and pa sswo rd , th ey wiLl b e co nn ec ted to hi g hly qualified e- in s tru c tor s™ who provide additional, interactive online tutoring on th e major co ncep t s of ph ys ics. Some re striction s apply ; offer s ubj ec t to c hange
• A ct"\v ActivPhysics OnLine™ (accesse d v ia www. physcs ma s te rin g phy s ics.co m ) , provid es s tudent s with a s uite of hi g hl y rega rd e d applet-based tutorial s (see above). The followin g workbooks help student s work though co mple x concepts and under s tand th e m more clearly. Th e A ctiv Ph ysics margin i co n s throu g hout the book dire c t s tud en t s to s p ec ifi c exercises that co mplement the textbook di sc u ss ion .
We have relied upon conversations with and , es pecially, the written publication s of many memb e rs of th e phy s ic s education community. Tho se who may recog niz e their influ e nc e include Arnold Arons, Uri Ganiel, Fred Goldberg, Ibrahim Halloun, Richard Hake, David He stene s, Leonard Jo ssem, Jill Larkin, Pri sc illa Law s, John Maliinckrodt, Lillian McD e rmott , Edward "Joe" Re di s h, Fred Re if, John Rigd e n, Rachel Scherr, Bruce Sherwood, David Soko loff, Ronald Thornton, Sheila Tobias, and Alan Van Heul even.
We are gratefu l to Larry Smith , Pawan Kahol , and Marilin Simon for the difficult task of writing the Iflstru ctor Solutions Manuals; to Jim Andrews for coauthoring th e Student Workbook (a nd lit era ll y writing out all its answers, with th e assistance of Rebecca L Sobinov sky); to Wa y ne Anderson, Jim Andrews, Nancy Beverly, Da v id Cole, Karim Diff, Jim Dove , Marty Gelfand, Kathy Harper , Charlie Hibbard , Robert Lutz, Matt Moeher, Kandiah Manivannan, Ken Robinson , and Cindy Schwarz-Rachmilowitz for th e ir contributions to the end-of-chapter questions and probl e ms; to CharLie Hibbard again for helping with the lecture PowerPoints; to Wayne again for he lping with the Tes t Bank qu estio ns; and to Steven Vogel for his careful review of the biological content of many chapters and for helpful sugge stion s
We especially want to thank our edi tor Jim Smith, development ed itor Alice Houston , proj ect ed itor Martha Stee le, production supervi sors Nancy Tabor and CamiUe Herrera, and
Reviewers and Classroom Testers
all the other staff at Pearso n Addison-Wesley for their enthusiasm and hard work on th.i s project. Ro se Kernan and the team at Nesbitt Graphics, Inc. , copy editor Carol Reitz , and photo re sea rcher Eric Schrader ge t much credit for makin g thi s complex project all come to ge ther. In addition to the reviewers and classroom testers )j sted be low, who gave in va luable feedback we are particularl y gratefu l to Ja so n Harlow for hi s clo se sc rutin y of every word , sy mbol , number, and figure.
Randy Knight: I would lik e to thank my Cal Poly colleag ue s, especia ll y Matt Moelter, for man y valuable conversa tion s and s ug gest ion s. r am endlessly g rateful to my wife Sally for he r lov e, e ncoura ge me nt , and patience, and to our man y cats for nothing in particular other than being cats.
Brian Jones: T would like to thank my fe llow AAPT and PlRA me mb e rs for th e ir in s ight and id eas, the creative s tudents and colleagues who are my partners in the Little Shop of Phy s ic s, th e s tudents in my Co ll ege Physics c la sses who help me become a be tt e r teac her, and, mo st of all , my wife Caro l, my be st friend and gentlest editor, whose love mak es the journey worthwhile.
Stuart Field: I would lik e to thank my wife and m y children, Sam and E ll en , for their lov e, s upport , and e ncouragement.
Special thanks go to our seco nd edition review pane l: Jim Andrews, Taner Edis , Marty Gelfand, Ja so n Harlow , Charlie Hibbard , Fred Jarka , Gary Morri s, and Bruce Schumm.
Susmita Acharya, Cardinal Stritch University
Ugur Akgun, Universit y of Iowa
Ralph A lexa nd e r, University of Missouri-Rolla
Donald Anderson , Iv y Tech
Steve Anderson, M ontana Tech
Jam es Andrews, Youn gstown State University
Charles Ardary, Edmond ComnulIlity College
Charles Bacon , Ferris State Universit y
John Barry, Hou sto n Community College
David H Be rman , University of Northem Iowa
Phillippe Binder, Universit y of Hawaii - Hilo
Richard Bone, Florida Int ernational University
J eff Bodar! , Chipola College
Jame s Borgardt, Juniata College
Daniela Bortoletto, Purdue Universi ty
Don Bowen, Stephen F Austill. State University
Asa Bradley, Spokane Falls Community College
Elena Brewer, SUNY al Buffalo
Dieter Brill , University of Maryland
Hauke Busch, Augusfa Stafe Universit y
KapiJa Casto ldi , Oakland University
Michae l Cherney, Creighton University
Lee Chow, Universit y of Ce nt ral Florida
Song Chung, William Patersoll Ulliversit y
Alice Churukian, COllcordia College
Kri sti Concannon, Kings College
Ternan Cooke , Georgia Perimeter College at Lawrenceville
Jesse Cude , Harlll ell College
Melj ssa H. Dancy, Universit y of Norrh Carolina at Charlotte
Loretta Dauwe , University of Michigall - Flim
Mark Davenport , S(m Allfollio College
Lawren ce Day, Utica College
Carlos Delgado , Commullity College of Southern Nevada
David Donovan , Nortizem Mi c higall University
Archana Dube y, University of Central Florida
Andrew Duffy, BO STon University
Taner Edis, Truman State University
Ralph Edwards, Lurleen B. Wallace Community College
Steve Ellis, Ulliversify of Kellfllcky
Paula Engelhardt, Tennesse e Tee/llti ca l University
Davene Eryes, North Seal/Ie Commullity College
Gerard Fasel, Pepperdille Ulliversify
Luciano Flei sc hfre sse r, OSSM Auo)! Te ch
Cynth.ia Galovi c h, University of Norrhern Colorado
Be rtram Gamory, Monroe Commullify College
Delena Gatch , Georgia Southern University
Martin Gelfand , Colorado State University
Terry Golding, Ulliversily ofNorfh Texas
Robert Gramer, Lake Cify Coml1lllllify College
William Gregg, Louisiana State Universit y Paul Gresser, Universify of Marylalld
Robert Hagood , Wa shtellaw Community College
Jaso n Harlow, Ulliversify of Torol/to
Heath Hatch , Ulliversify of MassachusellS
Carl Hayn , Sallta Clara Universify
Jame s Heath, Austin Communit y College
Greg Hood , TidelVafer COl1l11ltmify College
Sebastian Hui, Florence-Darlin gfol/. Tee/lIliai/ College
Joey Hu ston , Mi chigan State University
David Iad evaia , Pima Community College-East Campus
Erik Jen se n, Chemeketa Commu1Iity College
Todd KaLisik, Northem Tllin ois Ulliversity
Ju H. Kim , Uiliversity ofNorfl! DakO/{l
Armen Kocharian , California Slate University Northridge
J. M. Kowal s ki, Ulliversity of North Texa s
Laird Kram e r, Florida IllfernaliOlwl Uiliversity
Chrisopher Kulp , Eastern Kel/tu cky Ulliversity
Richard Kurtz, Louisiana State Ulliversity
Ke nneth Land e, Ulliversity of Penns y lvania
Tiffany Landry, Fol som Lake College
Todd Leif, Cloud County Communit y College
John Levin , Uiliversity of Tellllessee-Klloxville
John Lindberg , Seattle Pacific University
Rafael Lopez-MobiLia, The Ulliversity of Texas at Sail Antollio
Robert W. Lutz, Drake University
Lloyd Makorowit z, SUNY Farmingdale
Eric Martell, Millikill Ulliversity
Mark Masters, Illdi ana Ulliversity-Purdue
Deni se Meek s , Pima Community College
He nry Merrill, Fox Valle y Techllical College
Mike Meyer, Mi ch igall Tecllllolo gical University
Karie Meyers, Pima Community College
Tobia s Moleski , Nashville State Tech
April Moore , North Harri s College
Gary Mom s, Rice Ulliversit y
Me redith Newby, Clemson Ulliversit y
David Nice, Bryn Mawr
Fred Olness , Southern Methodist University
Charles Oliver Overs treet , Sail Antollio CoJ/ege
Paige Ouzt s, Lander University
Ru sse ll Palma , Minllesota State University-Mankato
Ri c hard Panek, Florida Gulf Coast Ulliversify
Jo shua Phiri, Florence -Darling Techn.ical College
Iulia Podariu , University of Nebraska at Omaha
David Potter, Austin Community College
Pro mod Pratap. University of North CarolillaGre e nsboro
Michael Pravica, University of Nevada, Las Vegas
Earl Prohofs ky, Purdue Ulliversit y
Marilyn Rand s, LllIvrell ce Techllo logical Ulliversity
Andrew Rex , University of Puget Sound
Andrew Richter, Valparaiso University
Phyli ss Salmons , Emb/ )! -Riddle Aerollautical University
Michael Schaab , Maill e Maritime A cademy
Bruce Schumm, Ulliversity of Califomia. Santa Cruz
M.i z uho Schwalm , Ulliversity of MilllleSOla CroOkstOIl
Cindy Schwarz , Vassar College
Natalia Semushkhina, Shippensburg University
Khazhg ery (Jerry ) Shakov, Tulane Ulliversity
Bait Sheinberg, Houst oll Community College
MarUin Simon, Auburn Ulliversit y
Ke nn e th Smjth , Pelllls ylvania Slate University
Michael Smutko, NorthlVestem Ulliversity
Jon Son, Bostoll University
Noel Stanton , Kallsas Slate University
Donna Stokes, University of Housto n
Chuck Stone, North Carolilla A&T
Chun Fu Su , Mis s issippi Slate University
Jeffrey Sudol , West Chester University
William Tireman, Northerll Michi ga ll University
Negussie Tirfessa, Mallchester Community College
Rajive Tiwari , Be /mom Abbey College
Charley My les, Texas Tech Universiry Preface
Herman Trivilino, College of the Mainland
Dougla s Tus sey, Penll sylvallia State Ulliversify
Stephen Van Hook , Penlls ylvallia State Ulliversity
Jame s Vesenka , Ulliversity of New Englalld
Christos Valiolis , Allfelope Valle y College
Stamatis Voko s, Seattle Pacific Ulliversity
Jame s Wanlis s, Embry-Riddle Aeronautical Ulliversit y
He nry Weig e l, Arapahoe Commullity College
Courtney Willi s, University of North em Colorado
Katherine Wu , Ulliversity of Tampa
Ali Yazdi, J effersoll Slate Community College
David Young, Louisiana State University
Hsiao-Li ng Zhou, Georgia State Ulliversit y
Ulrich Zurcher, Cleveland State Ulliversity
Preface to the Student
The m ost incomprehens ible t h ill g abo tt ! the un i verse is fha ! if is co m p rehensible. - A lbe rt E in s te in
[f yo u a re takin g a co ur se fo r w hic h thi s book i s ass ig ne d , yo u p ro b a bl y ar e n ' t a ph ys ics m aj o r o r a n e ng in eer in g m aj o r I t's lik e ly th a t yo u a re n ' t m aj o rin g in a ph ys ical sc ie nce. S o w h y a re yo u takin g ph ys ics?
It 's a lm os t ce rt a i n th a t yo u are tak in g p hysics because y ou are majo rin g in a d isciplin e th a t req uir es it. So meo ne , so mew he re, h as d ec id e d t ha t it 's impo rt a nt fo r yo u to take thi s co ur se . A nd th ey a re ri g ht. Th e re is a lo t yo u ca n lea rn fro m ph ys ics, eve n if yo u d o n ' t plan to be a ph ys ici s t. We reg ul arl y hea r f ro m d oc to rs, ph ys ica l th e rap ists, bi o log is t s and o th ers t ha t ph ys ics was o ne of th e most int e res tin g and valuabl e co ur ses th ey to o k in c oLl ege
So, wh a t ca n yo u ex pec t to le arn in thi s co ur se? Le t 's sta rt b y tal k in g a b o ut w hat ph ys ics is. Ph ys ics is a way o f thinkin g a b o ut th e ph ys ica l a s pects o f na tur e. Ph ys ics i s no t a bo ut " fac ts ." It' s far mo re foc u sed o n di scove rin g rela t ionships be twee n f ac t s a nd th e pa tr ems th a t ex i s t in nature t h a n o n lea rnin g fac ts fo r th e ir ow n sake. O u r e mph as is w ill b e o n thinkin g and reaso nin g. We a re go in g to loo k fo r pa tt e rn s a nd rel a ti o ns hip s in na tur e, de ve lo p th e log ic th a t re la tes d iffe re nt i d eas, a nd searc h fo r t he rea so n s why thin gs h a ppe n a s th ey do.
On ce we've fi g ure d o ut a pa tt e rn , a set o f re la ti o ns hip s, we' ll loo k a t appli ca ti o n s to see w he re thi s un de r sta ndin g takes u s. Le t's look a t a n exa mpl e . Pa rt (a) of th e fi gure s hows an e arl y mec ha ni cal clock. T he clock u ses a pe n d ul um, a ma ss s u s pe nd e d by a thin ro d free to pi vo t a b o ut it s e nd , as it s tim e kee pin g e le me nt. Wh e n yo u st ud y osci ll a tor y mo t io n, yo u w ill lea rn a bo ut the mo ti o n o f a p e ndulum Yo u'U lea rn th a t t he period of it s mo ti o n, t he t im e fo r o ne swi n g, d o es n ' t d e p e nd o n th e a mplitud e, t he s ize o f th e sw in g. Thi s ma kes a pe ndulum th e id ea l ce nt er pi ece o f a c loc k
B ut th e re a re o th e r sys te m s th a t look lik e pe nd ulum s too. Th e g ibb o n in p a rt ( b ) o f t he fi g ur e i s mov in g th ro u g h th e t rees b y sw in g in g fro m s uccess i ve handh o lds.
Th e g ibbo n 's mass is s u s pe nd e d b e low a p o int a b o ut w hi c h it is free to pi vo t , so th e g ibb o n 's moti o n ca n b e un de rs to o d as pe ndulum mo ti o n. Yo u can th e n u se yo ur know led ge o f p e ndulum s to d esc rib e th e mo ti o n, exp l ainin g, fo r ex ampl e, w hy th is g ibb o n is ra is in g it s fee t as it sw in gs.
L ik e a ny s ubjec t, ph ys ics is bes t lea rn ed b y d o in g. " D o in g ph ys ics" in thi s co ur se mea n s so lv in g p rob le ms, a ppl y in g w h a t yo u ha ve lea rn e d to a n swe r qu estio n s a t th e e nd of t he c h a pt e r. Wh e n yo u are g i ve n a ho mewo rk ass ig nm e nt, yo u ma y fin d yo urse lf te mpt ed to s impl y so lve th e probl e ms b y thumbin g th ro u g h the te xt lookin g fo r a for mul a th a t see m s li ke it w iJJ work. Thi s is n ' t how to d o ph ysics ; i f it was, w hoever requir ed yo u to ta ke thi s co ur se wo uldn ' t b ot he r. Th e fo lk s w ho d es ig ned yo ur maj o r wa nt yo u to lea rn to reason , no t to " plu g and c hu g " Wh a tever yo u e nd u p stud y in g o r do in g fo r a ca reer, thi s abiLit y w ill se rve yo u we ll. A nd th a t 's w hy so meo ne, so mew he re, wa nt s yo u to tak e ph ys ics.
(a ) Pendulu m cloc k
(b ) Gibbon locomo ti on
How do yo u lea rn to rea so n in thi s way? Th e re 's no s in g le s trateg y for study ing physics that will work for all st ud e nt s, but we can make some s u ggestio ns that will cCltainly he lp:
• Read each chapter before it is discussed in class. Class attendance is mu c h less effect ive if you hav e no t prepa red Wh e n you first rea d a chapter, focus on learning new vocab ular y, definitions, and notation. You won't understand w hat 's be ing discussed or how the ideas are being used if yo u don ' t know what th e terms and sy mbol s mea n.
• Participate actively in class. Take note s, ask and answer questions, take part in discussion g roup s. There is ample sc ientific evidence that ac1ive participation is far mor e effec tive for lea rning sc ie nce than is pa ss ive li sten in g.
• After class , go back for a careful rereading of the chapter. In your seco nd rea din g, pay close attention to the details and the worked examp les. Look for the logic behind eac h exa mple , not just at what formula is being use d. We hav e a three- s te p process by which we solve aJl of the worked examp le s in th e text. Most c hapt ers have detailed Problem-Solving Strategies to he lp you see how to apply thi s proce dure to particular topics, and Tactics Bo xes that exp lain spec ific steps in yo ur analysis.
• Apply what you have learned to the homework problems at the end of each chapter. By foll ow in g the techniques of the worked examples. applying the tacti cs and problem-solving stra tegies, you'lJ learn how to apply th e knowledge you are gai nin g. In short , yo u ' ll lea rn to reaso n lik e a ph ys ic ist.
• Form a study group with two or three classmates. Th e re's good ev id e nce that s tud en ts who stud y re g ularl y with a gro up do better than th e rugged individuali sts who try to go it alone.
And we ha ve o ne final s u gges tion. As yo u read the book, tak e part in class, and work through problems, ste p back every now and then to appreciate the big picture. You are going to stud y topics that range from motion s in th e so lar sys tem to th e electri cal s ignal s in th e ner vo us system that let yo u order yo ur hand to turn the pages of this book. You will learn quantitative met hod s to calc ulat e thin gs such as how far a car will move as it brakes to a stop and how to build a solenoid for an MRT machine . It 's a remarkable breadth of to pic s and tec hniqu es that is ba sed on a ve ry compact se t of organizing principl es. It 's quite re markabl e, reall y, well worthy of yo ur s tud y. Now, let 's get down to work.
Real-World Applications
Applications of biological or medical interest are marked BID in the li st below. MeAT- s tyle Passage Problem s are marked BID below. Other end-of-c hapter problems of biological or medical int erest are mark ed BlO in th e chapter. "Try It Yourself' experime nt s are mark ed TIY .
Chapter 1
Deprh gauges 6
BID Scales of nerve cells vs ga laxies 11
Accuracy oflongjumps 12
Tty How raU are you reaUy! 12
Mars Climate Orbiter: unit error 15
Navigating geese 23
Chapter 2
BID Tree rings 34
Crash cushions 42
Solar sails 45
BID Swan's rakeoff 47
BID Chameleon rongues 48
Runway design 51
Braking distance 52
TIY A reaccion rime challenge 53
BID A springbok's pronk 55
BID Cheerah vs. gazelle 57
Chapter 3
BID Fish shape for lungingvs. veering 72
Designing speed-ski slopes 80
Oprimizingjavelin throws 82
TIY A game of catch in a moving vehicle 86
Hollywood srunrs 86-87
Physics of fielding 89
Designing roller coasters 92
BID Record-breaking frogjumps 93
Chapter 4
Voyager and Newton's first law 103
Tty Gerring rhe kerch up our 104
Searbelrs and Newton's first law 104
Racing bike drag 111
Tty Feel rhe difference (ine"ia) 115
driver mass 116
Bullers and Newron'srhird law 122
Rocker propulsion 122- 123
A mountain railway 123
Chapter 5
TIY Physics scudents can't jump 141
Weighrless astronauts 142
Anri -lock brakes 146
Skydiver rerminal speed 150
BID Tracrion 154-155
Sropping disrances 157
Chapter 6
Clockwise clocks 170
Rotation of a compact disc 172
Scottish heavy hammer throw 173
Car cornering speed 176-177
Wings on Indy racers 177
Banked racetrack turn s 177
BKl Maximum walking speed 178
BID How you sense "up" 180
Fast-spinning plancts 180
BID Cenrrifuges 18 1
TIV Human centrifuge 182
Rotating space stations 184
Variable graviry 187
Walking on rhe moon 188
Huming wirh a sling 191-192
Chapter 7
Srarring a bike 206
Designing wheelchair hand-rims 206
Turning a capstan 208
Camera stabilizers 211
TIV Hammering home inertia 214
Golf putter moment of inertia 217
Rolling vs. s lidin g: ancient movers 22 1
Spinning a gyroscope 222
Chapter 8
BID Muscle forces 233
BID Finding rhe body 's cenrer of graviry 236
Rollover safery for cars 237
Tty Balancing soda can 238
BID Human srabiliry 239
Tty Impossible balance 239
Elasriciry of a golf ball 240
BID Spider silk 244
BID Bone s tren g th 244-245
Chapter 9
BID Oprimizing frogjumps 263
Tty Warer balloon carc h 265
BID Ram skull adaprarions 265
BID Hedgehog spines 265
BID Squid propulsion 273
Ice-skating spins 278
Hurricanes 279
Aerial 6refighring 280
Chapter 10
Flywheel energy storage on the I SS 300
Why racing bike wheels are lighr 301
BID Energy srorage in rhe Achilles rendon 304
TIV Agitating Jroms 305
BID Jumping locusrs 307
Crash helmers 312
Runaway-truck ramp s 314
Chapter 11
BID Energy in rhe body: inpurs 326
BID Calorie conrenr of foods 327
BID Energy in th e body: omputs 327
BID Daily energy use for mammals and rep riles 329
BID
Energy and locomorion 331
Optical molasses 333
Temperature in space 334
TI Y Energetic cooking 335
Refrigeracors 341
Revecsible heat pumps 342
TIY Typing Shakespeare 345
BlO
En[[opy in biological syscems 347
Efficiency of an automobile 348
Chapter 12
Infrared images 362,393,394
Frost on Mars 366
Swim-bladder damage co fish 368
Diffusion in the lungs 370
Chinook winds 377
Thermal expansion joints 379
TIY Thermal expansion to the rescue 380
BID Survival of aquatic life in winter 381
Hurricane season 382
Tin pest 383
BID Frogs that survive freezing 383
Keeping cool 384
Gasoline engines 390
Carpet vs. tile for comfort 392
Penguin feathers 393
Heat transfer on earth 394
Breathing in cold air 395
Ocean temperature 403
Chapter 13
Submarine windows 409
Pressure zones on weacher maps 411
Tire gauges 411
Barometers 412
BIO Measuring blood pressure 414
BIO Blood pressure in giraffes 414
BIO Body-fat measurements 416
Floating icebergs and boats 417
Hot-ait balloons 419
TIY Pressure forces 424
Airplane lift 424
BIO Prairie dog burrows 424
BID Measuring arterial pressure 425
BID Cardiovascular disease 429
BID Intravenous transfusions 430
BID Blood pressure and flow 437
BID Scales of living creatutes 439
Chapter 14
BID Heart rhythms 445
Metronomes 451
BID Bitd wing speed 452
TIY SHM in your microwave 454
Swaying buildings 455
Measuring mass in space 457
BID Weighing DNA 458
Car collision rimes 460
Pendulum prospecting 460
BIO Animallocomotion 462
TIY How do you hold your arms! 462
BID Gibbon brachiation 462
Shock absorbers 464
Tidal resonance 465
Musical glasses 466
BID Hearing (resonance) 467
Springboard diving 467
BID Spider-web oscillations 476
Chapter 15
BID Echolocation 477,488, 506
BID Ftog wave-sensors 480
BIO Spider vibration sense 481
TIY Distance co a lightning strike 483
BKl Range of hearing 488
Sonar imaging 488
BKl Ultrasound imaging 488
BID Owl ears 490
BID Blue wha le vocalization 492
Hearing in mice 493
BKl Hearing (cochlea hairs) 494
Solar surface waves 495
Red shifts in astronomy 497
BID Wildlife tracking with weathet radar 497
BID Doppler ultrasound imaging 498
Earthquake waves 499
Chapter 16
BID Shock wave lithotripsy 509
T I Y Through the glass darkly 512
The Tacoma bridge standing wave 515
Suing musical instruments 515
Microwave cold spots 516
BID
Resonances of the ear canal 519
Wind musical instrumencs 520
Speech and hearing 521
Synthesizers 521
Vowels and formants 522
Saying "ah" 522
Aerive noise reduerion 524
Controlling exhaust noise 526
BKl The bat detector 528
Dogs' growls 529
Harmonics and harmony 537
Tsunamis 539
Chapter 17
TIY Observing interference 551
CD colors 556
BID Iridescent feathers 558
Antireflection coatings 558
Colors of soap bubbles and oil slicks 560
TIY Observing diffraction 565
Laser range finding 566
BID The Blue Morpho 573
Chapter 18
Shadow in a solar eclipse 578 mirrors 580
Optical image stabilization 583
Binoculars 584
Snell's window 585
Optical fibers 585
BKl Arthroscopic surgery 585
BIO Mirrored eyes (gigantocyptis) 594
Supermarket mirrors 596
Optical fiber imaging 601
Mirages 608
Chapter 19
BKl The Anableps "fout-eyed" fish 609
BKl A Naurilus eye 610
Cameras 610
BID The human eye 613
TlY Inverted vision 613
BID Seeing underwater 614
BKl Neat- and fatsightedness 615
Forced perspective in movies 6 17
BKl Microscopes 618-620,627
Telescopes above the atmosphere 621
Rainbows 623
BKl Absorption of chlorophyll 624
Fixing the HST 625
BID Optical and eieerron micrographs 627
BKl Visual acuity for a kestrel 629
BIO The blind spot 631
BID Surgical vision correction 635
BID Scanning confocal microscopy 637
Chapter 20
BKl Gel electrophoresis 642,664
TIY Cha rges on tape 645
TlY Pulling water 648
Bees picking up pollen 648
Hydrogen bonds in DNA 651
Separating spe rm cells 652
Electrostatic precipitators 660
Electric field of the heart 661
Static protection 663
Lightning ro d s 663
Electrolocation 663
Cathode-ray tube s 665
Flow cytometry 674
Chapter 21
BID Electropotencials around th e brain 675
Cause oflightning 679,711
Membrane potential 680
Medical linear accelerators 683
Shark elecrroreceptors 692
The electrocardiogram 694
Random-access memory 697
Camera flashes 700
00 Defibrillators 700
Fusion in the sun 702
Chapter 22
BID Percentage body - fat measurement 712,730-731
Monito ring corrosion in power lin es 714
TIY Listen to you r potencial 718
The electtic torpedo tay 719
Fuel ce lls 719
Lightbulb filaments 722
Testing drinking water 723
00 Impedance tomography 723
Photoresistor ni ght lights 725
Cooking hot dogs with electricity 728
Lightbulb failure 738
Chapter 23
00 Electr ic fish 739,775
C hri s tm as- tre e li ghts 745
H ead light wiring 747
Transducers in measuring devices 749
Flashing bike light 755
Inrermittenr windshield wipers 757
BID Electricity in the nervous system 757-764
BID Electrical nature of nerve and muscle cells 758
BID Inte rpreting brain clecrrical potentials 762
Soil moisture measuremenr 765
BKl Cardiac defibrillators 774
Chapter 24
BIO Magnetic re sonance imaging 776,789
TIY Buzzing magnets 780
Hard disk data storage 781
BKl Magnetocardiograms 787
The au rora 793
BID Mass spec trometers 794
BID Electromagne t ic flowm eters 795
TlY Magnets and TV screens 795
Electric motors 802
BK) Magnetotactic bacteria 804
Loudspeaker cone function 805
The velocity selector 814
Ocean potentials 815
Chapter 25
BlO Co lor vision in anima ls 816,840
BID Exte rnal pacemaker programming 8 17
BKl Shatk navigation 819
Generators 821
TlY Dynamo flashlights 821
C redit card readers 826
Magnetic braking 828
BID Transcranial magnetic st imul a t ion 829
Radio transmission 830
The so lar furnace 832
Polarizers 833
Polarization analysis 834
00 Honeybee navigation 834
TlY Unwanced tran smissions 837
Co lors of glowing objects 838
BIO Infrared sensors in snakes 839
Astronomica l images 841
Tethered satellite cir cuits 841
Metal detectors 851
Chapter 26
Charging electric tOothbrushes 856
Transformets 855-857
Power transmission 858
Household wiring 859
BlO Electrical safety 861
The li ghtnin g crouch 862
TIV TestingGF I ci rcuits 863
Laptop trackpads 864
Under-pavement car detectors 866
Cleaning up comp uter power 867
BIO Nuclear magnetic resonance 870
The ground fault interrupter 871
Halogen bulbs 879
T h e greenhouse effect 881
Chapter 27
Global Positioning Systems 886, 902 , 913-914
The Stanford Linear Accelerator 905
Hype rspace in movies 910
Nuclear fission 913
00 Pion therapy 921
Chapter 28
00 Electron microscopy 922,936
00 X -ray imaging 923
BlO X -ray diffraction of DNA 925
BlO Biological effects of UV 928
00 Frequencies for photosymhesis 929
BIO Waves, photons and vision 931
Hi gh -ene rgy moon light 932
TIV Photographing photOns 933
Scanning tunneling microscopy 943
BID Ma gnetic resonance imaging 945
Chapter 29
00 Spectroscopy 955
Colors of nebulae 956
Sodi um fi lters for telesco pes 977
00 Fluorescence 979
BlO LASIK surgery 982
Compact fluore sce nt li g hting 982
Light -e mitting diodes 990
Chapter 30
00 Bone scans 991, 1010
Measuring past earth temperature 993
Nuclear fusion in the sun 996
Nuclear power 997
Plutonium "batteries" 1006
00 Radiocarbon dating 1007
BIO Radioactive isotopes for medicine 1002
BID Gamma-ray medical ste riliza tion 1008
BIO Radiation dose from environmenral, medical sources 1009
00 Nuclea r medicine 1009
00 Nuclear imaging, PET scans 1010-1012
Cerenkov radiation 1015
Nuclear fission 1022
Using Energy
11 .1
11.2 Energy in ,he Body: Energy Inpurs
11 3 Energy in ,he Body: Energy Ourpurs
11.4 Thermal Energy and Temperature
11.5 Heat and t h e First Law of Thermodynamics
11.6 Heat Engines
1
11
Enrropy and , h e Second L aw o f Thermodynamics
11.9 Sysrems, Energy, and Enrropy
SUMMARY
Properties of Matter
Modern Physics
These images of animal eyes and light- sensing organs reveal the wide range of structures that can produce a visual sense. There is a certain similarity among eyes as well; did you spot the false eyes , patterns that are designed to mimic the appearance of an eye?
Light Is a Wave
Ts
p a rti c ular, li g ht is an e lec trom ag ne ti c wave, althou g h th ese c hapt e rs d e pe nd on nothin g m o rc than th e " wa v in ess" o f li g ht waves f o r yo ur und e rs t a ndin g. Th e wa ve th eo ry we d eve lo pe d in Pm1 TV will b e put to go od u se in Part V a s we beg in our in ves ti ga ti o n o f li g ht and opti cs with an an a lys is of th e wa ve m o d e l o f li g ht.
The Ray Model
Ye t N ewt o n wa s c orrec t in hi s obser v ation th a t li g ht s e e m s to tr av el in s trai g ht line s, so m e thin g w e w o uldn ' t ex p ect a w ave t o do . C on se qu e ntl y, o ur in ves ti gati o ns o f how li g ht w o rk s will be gr eatl y aid ed by anoth er model o f li g ht , th e ray mo d el, in whi c h li g ht tra ve ls in s trai g ht lin es, boun ce s from mirrors, and is bent by l enses.
Th e ra y m o d e l will b e an exc ell e nt t oo l for analy z in g man y o f th e practi c al appli ca ti o ns of opti cs. Wh e n yo u lo ok in a mir ro r, you see a n im age o f y ourse lf th a t a ppe ar s to b e b e hind th e mirror. We will u se th e ray mod e l of li g ht to de te m1in e ju s t h ow it i s that mirrors and le n ses fo rm ima ges. At th e s am e tim e, we w ill nee d t o re con c il e the wa ve and ra y mod e Js, le arning ho w the y are re lated to eac h oth e r and w he n it is appropri a te to u se e ac h.
Working with Light
Th e natur e o f li g ht is quit e s ubtl e and e lu s iv e. In Part s VI and vn , we will turn to the qu es ti o n of ju s t w hat li g ht i s . A s we w ill see , li g ht ha s b o th w ave- lik e an d p a rticl e- lik e as pec ts . Fo r now, h o w eve r, we will se t thi s qu es ti o n as id e and wo rk with the w av e a nd ra y m o d e l s to d eve lo p a pra c ti ca l und e r s tandin g o f li g ht. Thi s w ill le ad u s, in Chapt e r 19, to an a nal ys is of s om e common o pti c al in s trum e nts We w ill ex pl o re h ow a c am e ra c aptur es ima ges and h o w te lesco p es and mi c ro sc op es w o rk . Ultim a t e ly, th e fa c t that y ou are re adin g thi s book is du e to th e opti cs o f the fir st o pti cal in s trum e nt yo u eve r ll sed , yo ur eye! We w ill in ves ti g at e th e o pti cs o f th e eye, le arn ho w th e c orn ea a nd le n s be nd li g ht to c rea te an im ag e on yo ur re tin a, a nd see h ow g la sse s or c ontac t le n ses c an b e u s ed to correc t th e ima ge s h o uld it be o ut of fo c ll s.
LOOKING AHEAD
Th e go a l of Ch a pte r 17 is t o understand and use t h e w a ve m odel of lig ht
What Is Light?
You'lIlcarn th at li g ht h as aspects o f waves, rays, and parti cles. We ' ll develop mod e ls for eac h of t hese in thi s a nd coming c hap ters; t h is c hapte r w i ll concen t rate on th e wave mode l of lig h t.
The colors of soap bubbles can be understood u sing th e w a ve m o d e l of ligh t
Looking Back
15 .4 Ught and elec trom agne ti c waves
To understand the bending o f l ight by a co nta c t lens, the r ay mode l (C hapter 18) is a ppr o priate.
Solar cells generate e lectri city from sunlight. We'll u se the ph o t o n mo del (C hapter 28) t o understand how.
Interference of Light
Like a ll waves , li g ht wave s of t he sa me f req ue ncy ca n int e rfere co ns tru c ti ve ly or d est ru ct i ve ly.
Double·slit interference
When li g ht s hin es o n two narrow , cl osel y s paced s lits, inte rfe re nce frin ges a re see n on a sc reen be h i nd t he s lit s. Interference is a clear indi ca tion o f the wave nature of li g h t.
The diffraction grating
Fringes see n with green lig ht.
Many c lo se ly s paced s l its or g ro oves form a di tTract io n g r a tin g, ca pab le of break ing whi te li g ht into it s compo ne nt co lors.
The m icrosco p ic grooves i n a CD act as a diffraction grating, leading t o its colo rfu l ap p eara nce.
Diffraction
One o f the m os t bas ic aspects o f waves is th at they can be nd . o r diffract. aro und the edges of objec ts. The d iffrac ti on of li g ht , a lth o u g h difficult to obse rve beca use of li gh t' s s m a ll wave length , is an in d icat io n that li g ht is a wave.
A careful exami nation of the sha dow of this razor blade s h ows fringe s due to d iffrac tion of li ght.
Thin·film interference
Int erference is al so po ss ib le be t wee n waves re fl ec t i ng o ff th e f ro n t and back s urfaces of a lhin transparent film.
Looking Back
15 .5 Circ ular and plane waves
16.3 Reflection s 16.6 Interference
The colors in an oi l slic k result f rom th i n film i nt e rfe r e n c e
