Feynman's Tips on Physics: A Problem-Solving Supplement to the Feynman Lectures on Physics

176 Pages·2005·4.11 MB·English

by  Richard P. Feynman

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Foreword
At a lonelbyo rdepro st hoing ht heH imalayafnr ontiRearm,a swamy
Balasubramapneiearne d thhriosub gihn oculaattr hse P eopleL'isb eration
Armys oldisetrast ioinneT di bet-whwoe rep eeritnhgr outghhe isrc opes
back at Theinms.i obnest weeInn diaan dC hinhaa db eenh ighf ors everal
yearssi nc1e9 62w,h ent het woc ountrtireasd sehdo tasc rotshse idri sputed
bord.e Trhe PLA soldiekrnso,w intgh eyw ereb einwga tchetda,u nted
Balasubramaannidha insf elloIwn diasno ldibeyrs sh akindge,f italn,yh igh
in thea irt,h eipro cket-sibzreidg,h t-croepdi eosf Quotatiofnrso m
ChairmaMna o-bettkenro wni nt heW esta s" Mao'Lsi ttRleed B ook."
Balasubramatnhieaann c,o nscrsitputd yipnhgy siicnsh iss partei me,
soong rewt iroefdt hestea untSsoo. n ed a,y hcea met oh iso bsevratipoons t
preparweidt ahs uitarbeljeo inAdses ro.o na st heP LAs oldisetrasr tweadv ­
ingM ao'sL ittRleed B ooki nt hea iarg aihne,a ndt wof elloIwn diasno l­
dierpsi ckeudp a ndh elda loftth et hrebei gb,r ight-vroeldu meosf T he
FeynmaLne cturoensP hysics.
Oned ayI r eceivae lde ttferro mM r. BalasubramHainswi aasna .m ong
hundreodfsl ettIeh rasv er eceivoevde trh ey eartsh adte scritbheel asting
impacRti charFde ynmahna sh ado np eoplel'isv eAsf.t erre counttihneg
"red-booiknsc"i deonntt h eS ino-Indfiraonn tiheewr r,o te":N ow,t wenty
yearlsa tewrh,o ser edb ookasr es tibleli nrge ad?"
IndeeTdo.d aym,o ret hanf ortyye arasf tetrh eyw ered eliverTehde,
FeynmaLne cturoensP hysiacrses tibleli nrge ad-ansdt iilnls pire--even
inT ibeIts ,u spect.
A specicaals ien p oinste:v eryaela rasg oI metM ichaeGlo ttliaetab
partwyh eret heh oswta sd isplayoinna g computer tshcerh eaernm onic
overtonofea s l ivTeu vant hroat-singkeirn-odtf he ev entth amta kesl iv­
ingn eaSra nF rancisscuoc hf unG.o ttliheabds tudimeadt ha ndw asv ery
interesitnpe hdy sicsso,I suggestheedr eadT heF e ynmanL ecturoens
Physics-aanbdo uat y ealra tehre,d evotseid xm onthosf h isl ifteor ead­
ingT heL ecturveesr yc arefuflrloym b eginnitnoge nd.A s Gottlieb
descriibneh si si ntroduttihoilnse, d e,v entu,at lolt yheb ooky oua rer ead­
ingn ow,a sw elals t oa n ew," DefiniEtdiivtei oonfT" h eF eynman Lectures
onP hysics.
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iv• F 0 R E W 0 R D
Thusa mpI l eatsheapdte opilnet erienps htyesdai lcolsv e trh weo rld can
now stwuihdtt yh,ae d ditoifto hnis su pplteamvleo nlumame o,r ceo rrect
ancd opmleetdei toifTo hneF eynmLaenc rteuso nP hysicmso-nau mental
wortkh awti ll cotnoit nifnoaurnemid s npisrteu defnodrte sc atdoec so me,
whethienmr i dtoMwann hatotrha ingi hnt hHei maylaas.
RalLpehi ghton
May11 2,0 05
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1962
Introduction
firshte aorfdR ichaFredy nmaannRd a lpLhe ighitn1o 8n9 6t,hr ough their
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entertbaoionSkir uneglY yo' eur JoMkr.Fi enmygan,nT h!i rtyeeeanlr ast er
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togetohnte hrde e siogfanf antsatsaymh po norFienygn maAnlt.lh weh ile
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ama c ompuptreorg ramFmeery)n Lmeacnt ounCr oemsp u2tT ahet ion.
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intrimgeu,be udwt i thhoauvti sntgu dqiueadn tmuemc ahnicIhs a,dd iffi­
culftoyl lotwhiaenr gg umeRnatlspr.he commenrdeeadTd h Fee ynman
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somqeu antmuemc han!Hi ocwsevtehra,gt o able camsee condaastr iym e
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inTg hLee cretfsulu -lti.m e
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thewreer vee rfye w erirnto hrasvt o lumHeo.w evearsI, p rogressed
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LectRualrpaehns Idw. e rseu rsperdhi:o wc ouslodm aneyr rohrasvb ee en
overlookseold o nfWgoe?rd ecitdoes de weh acto ubledd onaeb oguett ­
tintgh ecmo rreicntt henede xetd it.i on
Thenn oIt iscoemdei ntrisgeunitnegin nFc eeysn m'apsnr ef:a ce
"Three astohne arrene o l ectures osno lpvhroeow b ltieosbm esc ause
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wasa l ectounri en ertgiuailnd caweh icche rtaibnellyo anfgtste hrle e cture
onr otastyinsgt ebmuswth, i cwha su,n fortunoamtietl.ty"e, d
Thissu gsgteetdh ied eoafr ecsotnructthimeni gs sliencgt uarnedis,f
thepyr oviendte esrtionfegfr,i tnhge tmo C alt ecahn Add disWoesnl-efyo r
incluisnai m oonr ceo mplaentdee r ror-coerdrietcoitfoTe nhd L ee cetsu.r
Butf irIsh ta dt ofn idth e missinga ndIlw eacsst tuliri lenCs o,s tRai c!a
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thlee ctnuoretesw ,h icwhe rper eovuishliyd daewna syo mewhbeertew een
hifsa t'hesor fficaen dt heC alteAcrhhci veRsa.l pahl soob taitnaepde
recordoifnt ghsem issilnegc tuarneds ,w hile reseianrt chhei ng errata
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FeynmParnoe fsosro fT heorePthiycsaailtCc astl e c,wh hoe veunatlmlayn ­
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toa mentdh eex isvtoilnugm oefTs h Lee rcetfsou hri storreisacoanRlsa ,l ph
porpospeudt ttihnmegi sgsl ienctiunra es se parbaotoeTk h.a itst hoer igin
oft hissu pplemevnotlaurmIyeti .s b eipnugb liisnhp eadrl aewlli tahn ew
DfieniEtdiivotefTi hoFene ynLmeacrentos unP hysiniw hcisct,hhe e r rors
If ouanrdce o rreacsta erodet, h eerrr ofrosu nbdya n umboefro threera d.e rs
MatSta nd'sm emoir
Ino uqru etsotr econstthrfeuo cultre ctuRraelspa,hn dIh adm anqyu es­
tinosW.e feltf ovrteurntyaob t eea blteog eatn swefrrosPm r oefsrsM oatt
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produTcehFde e ynLmeacentso u nPr hysWei cwses.rue r prtihsatethd e
stoorfty h egiern ewsaisns o wti deklnoyw na,n dr ealitzhiatnthg ip rsjo cet
offeraenod p portutnori etmye dtyh adte ficPirtoe,fs sSoran dsk indly
agreteowd r iatm ee mooinrt he oroifTg hiFnees y nLmeacrentfs ou irn clu­
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dasyb efotrhefe i neaxla mS.o f,o trh wee epker cedtihntege sFte,y nnm a
gavteh roepet iornveailel we ctsu,ir nwe hicnhon ewm aterwiaasil n tro­
duceTdh.er evileewc twuerreiesn tenfdosertd u dehnatvsid nffiigc ultiine s
thcel aasnsed,m phastiezcehdn ifqouurne dse rstaannsddo ivlnignp gh ysics
prbolemSsom.e oft hee xmaplper olbemwse roef h istoirnitcseatrl,e
inclutdhideni gos vceorfyt haet omniucc lbeyuR su therafnotdrh dde,e ter­
minatoifto hnme a sosf t hpei m esoWni.t chh aractheurmiasintn isci ght,
Feynmaaslnod iscutshsseeol du titooan n otkhienrod fp rolbeme,q ually
importtoa nlatet ah satlt fhs et udeinnht isfs r sehmacnls ast:h eem otional
probloeffim n dionnge selfa vbeerl.ao gwe
Thef ourltehc tDuyren,a mEiffceaacntlTds h Aeppilri cwaatsgi iovenns ,
earilnyt hsee cotnedr omft hfer sehmacnl asshso,rt alfyt tehrse t udents
returnferdo wmi ntberre aOkr.i giniatwl alsty o,b eL ecet uarndt he
21,
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Septetmoeb aerDrle yc emtbhseeer c,fo rnoedma rJlayn utaoer ayrM layra cnhtd,h e
third Mfarrtoceomha Jrlnulaeyt. e
vii• iI N T R 0 D U C T I 0 N
rotoanptsri eseinnCt headp1 t8etrh sr o2u0ag nhsd h otwhs et udseonmtes
interaeplspittciinanosag n pdh ennoatm heaarti ser oftoranot"smuji, sf to r
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foirtd si scuosfts hiieon nc itprisaeinntitinr o ena l-timef rcoomm puting
anatlodo igg miettahlio n1d 69s2 .
Thee xercises
Int he cotuhrpisrjseoce tRo aflr peheb sltiaschoendtw aictthf aeht'rihss
goofder inadn cdo lglueReao chVuosgw th,go r caiougsalvhyeip sem ris­
sitoon rleipesuxhcbe irsaenssd ou ltoinfsr oEmxe rciinIs netsro ductory
Pyhsitchcseo ,l letchRtaoitbo Lener htit goannh deh acdr eaetsepde cially
foTrh Lee cretbsua ckt h1ie69n 0 .Ds uteos palciem itIac thiooosnnels y
exceirsfeoVsro luCmhea/p1,tt e hrrso u(gthh e2 0mc aotveebrreiefadol r e
DynamEiffceaaclntT dseh iArpp lincsap)tr,ie ofeprrrloiebnmtgsh atto,
quote LReoiobgneh"r,att nr uem iecraolral nya lystiimcpyaleliteln ,yc isive
anidl lutmiiinncng oa tne.n"t
Website
Readaerriesn t vetidov iwsiwtwe .yfnmcatneulsiren.ffoomr o rien forma­
tioonnt hviosl uamnTedh Fee ynLmearcentos un P hysics.
MikGeo ttlieb
PlaTyaam anrdioC,o sRtiac a
mg@f eynmanlencfto ures.i
Acknowledgments
We wtioes xhep srosu r hetahrattnofak elsll t whtoih bsmo aopdkoe s sible,
espieaclly:
ThomasT ombrellCo,hi armaonft hPeh syicMsa,t heimcasatn,d
AstroDniovmiyfs oiarop onpv,ri tnihgps r jocet boenh oafCl alfet cahn,d
CarlF eynmana ndM ichelFleey nmanh,e itroRs i crhdFa eynmfaonr,
thepiemrri sstiopo unb ltihsefhia rtr h'lese ctiuntri hebsso ok;
MattheSwa ndsf,o hriw si sdkonmo,w lceodnrgsuetc,tc iovmem e,an ntds
sugignoess;t
MichaeHla rtfl,oh rim se tuilcopurso aodfrioenftg h mea ncursiapntfdo, r
hidsi liwgoernkt t wheiert rhia nTt haFe e ynLmeacrentos un P hysics;
RochuEs. V ogtf,o trh ien genpirbooluesam nsad n srwsie nE xerciins es
IntrodPuhcytsaoinryfdc o hsri,p s em risstioo tnueh sme t iihnvs o l;u me
JohnN ee,rf osrt iuodudsolcyu meFnetyinn'mlgsae nucrtaetts h Heu hges
AirracCfotr poraanftdoi srohr nai,tn hgo sew tinhuo st;e s
HeleTnu ckF, eyn'mssae ncrfeotmraa rnyyye r a,sf ohre erno curagement
ansdu pport,
AdamB lackE,d i-tionri-efCfohP rhs yilSc caieanAtcd edsi Wseosnlf-eoyr,
hiesnh tusiaanspdme rsevienbri ranngctiihenvs go lutmope r ianntd,
KipT hornef,o hrig sr aacnetde i lrewsosrs ke cutrhitenr gua snstdu pport
ofe veriynovnoeal nvfdeo odrv, e rsoeuewrio nrgk .
ix