Ch_16_problems
8 Pages

Ch_16_problems

Course Number: PHY 142, Winter 2007

College/University: SUNY Stony Brook

Word Count: 10247

Rating:

Document Preview

5 30 C HAPTER 16 S uperposition a nd S tanding W aves S UMMARY T he g oal o f C hapter 16 has been t o u se t he i dea o f s uperposition t o u nderstand t he p henomena o f i nterference a nd s tanding w aves. G ENERAL PRINCIPLES P rinciple o f S uperposition T he displacemen t o f a medium when more than one wave is present is the sum o f th e di splacements due to each individual wave. I nterference In...

Unformatted Document Excerpt
Coursehero >> New York >> SUNY Stony Brook >> PHY 142

Course Hero has millions of student submitted documents similar to the one
below including study guides, practice problems, reference materials, practice exams, textbook help and tutor support.

Course Hero has millions of student submitted documents similar to the one below including study guides, practice problems, reference materials, practice exams, textbook help and tutor support.

30 C 5 HAPTER 16 S uperposition a nd S tanding W aves S UMMARY T he g oal o f C hapter 16 has been t o u se t he i dea o f s uperposition t o u nderstand t he p henomena o f i nterference a nd s tanding w aves. G ENERAL PRINCIPLES P rinciple o f S uperposition T he displacemen t o f a medium when more than one wave is present is the sum o f th e di splacements due to each individual wave. I nterference In general, th e superposit ion of two or more waves int o a s in gle wave is c a ll ed int erference. C onstructive i nterference occurs when D estructive i nterference occ ur s when crests crests are al igned w ilh c rests and troughs wilh are aligned with trough s. We say the waves are o ut o f phase. It occurs when the pathtroughs. We say th e waves are in phase. I t occurs when the path-le ngth difference !!1d is length difference !YJ.d is a whole number o f a whole number o f waveleng th s. wavele ngths plu s half a wavele ngth. " ~ ~ _-----'I\~-- " .p,~ " : ""J=lA " ~ '.f\ f \ f\ o ' x I I MPORTANT CONCEPTS S tanding W aves Two id e nti callravel in g waves mov ing in o pposite direction s create a smnding wave. Antinodes xXx Nodes A s tanding w ave o n a s tring has a node at eac h end. Po ss ibl e modes: m =l <=> C 5b 111=3 ( )(XJ O pen-open f,"~IIIGJ 111 = 1,2,3, . .. Closed -closed f,,,~m(;J 11/ = - - - Node spacing is ~A. The boundary cond iti ons determi ne which s ta nding-wave frequencies a nd wavelengths are allowed. The allowed stand in g waves are modes of the system. A s tanding s ound w ave in a t ube can have different bOllndary oo ndi t ion s: ope n- open, closed-c losed, or open-closed. L 1,2,3,. O pen-closed II 2L Am= In = 1,2,3, . . f,"~III(:J m = 1,3, 5,. . <:2 C><=2J tJ..p in tube <::::::: 111 = 1 L A PPLICATIONS B eats (loud-soft-loud-so ft modulation s o f inten s it y) are produced when two waves of s li ghtly different frequencie...;; are superimposed. Standing waves are multiples o f a f undamental f requency, th e frequency of lhe lowest mode. The hi gher modes are th e hi gher h armonics. For sou nd, the fundamental frequency determines the perce ived pitch; the hi gher harmo ni cs determine the tone qualily. Loud Soft Loud S oh Loud Soft Loud Our vocal cords create a range of harmon ics. The mi x o f higher harmo ni cs is changed by our vocal tract to c reate differenl vowel sounds. _ ____ Fu ndamental frequency . H igher harmonics ( \ + -c'-::--:"c-:-'-:-c"-::c-'---c'.::--L-:c':-:-f(H ,) 262 524 786 1048 1572 2096 Q uestions r-- T1oI For h omework assig n ed o n MasteringPhysics. g o t o ~ IMP . h' w ww.mastermgpyslcs.com Problems l abe led c hapters; Problem difficu l ty is labeled as I ( straightforward) t o 5 31 1M i nteg rate sig n ificant m aterial f rom e arlier BKl are o f b iological o r m edical interest. m (cha lleng ing). il Q UESTIONS C onceptual Q uestions I . L ight c an p ass e as ily through w ater and through air. but li ght w i ll reflect from t he s urface o f a l ake. W ha t d o es th is tell you a bo ll t the s peed o f li ght in a ir and in w ater? 2. O cea n w aves a re p artiall y r enecl ed from the e nlIance to a harbo r. w he re th e de pth o f t he w ater is s udden ly less. W hat d o cs th is te ll you a bolll the s peed o f w ave s in w a ter o f d ifferent d e pth s? 3. A str in g has an a bmpt c hange in li ne ar d ens it y at it s m idp o int s o t haI the s pee d o f a p ul se on the left s ide is 2/3 o f that o n the right side. a. On which side is the lin ea r dens it y greater? Ex pl ai n. b. From w hi ch s id e w o uld y ou s tart a pu lse s o that its re fl ect ion from th e midpoint would not be inverted ? Explain . 4 . A guita ri st find s that the f requency o f o ne o f her strin gs is too l ow by 1.4 %. Should she in crease o r d ecrease the tens io n o f t he strin g? Explain . 5. C e rt a in illn esses in n ame y o ur v oca l c ord s, c aus ing t hem to BID s wel l. H ow d oes thi s affect the p itch of yo ur vo ice? E xplain. 6. Fi g ure Q 16.6 s how s a s tanding w ave o n a strin g that is ose iLl atin g at freq ue ncy 10' How m an y anti nodes will there b e i f t he FIGURE 0 16 .6 f reque ncy is d oubled t o 2 / 0? E xplain . 7. Figure Q 16.7 s hows a s tanding ~ ~ ~ ~ eoe I I. BID 12. 13. 14. BID 15 . BKJ 16 . <:X:X:X:> so und wave in a tube or air that is open at both e nds. a. Whi c h mode ( va lue o f 11/) FIGURE 0 16 .7 s tanding wave is thi s? b. Is the air vibrat ing hori zontall y o r v ertically? 8. A t yp ica l flut e is a bout 6 6 e m long. A pi cco lo is a very s imi lar in s tr um ent , t hou gh it is s ma ll e r, w it h a length o f a bout 3 2 c m. H ow d oe s t he p itc h o f a p ic co lo c o mpare to that o f a fl ut e? 9. So me p ipes o n a p ipe o rga n a re o pe n at both ends, others are c lo sed a t o ne e n d . F or p ipes t hat play l ow-freq uency notes, the re is an ad vantage to usin g p ipe s that are c losed at o ne end. What is the a dvantage? 10. A flut e p layer tun es he r in strument w hen the a ir ( and the flut e) is c o ld . As she plays, the flute a nd the air in s id e il wa rm up . Both the changing s peed o f s o und in the a ir in s ide and the the rmal e xpa ns ion o f the flute affect the frequ ency o f the s o und w ave p roduced by the flute. After s ome time, she find s that her play in g is " s harp " -the frequ e ncies are too hi gh. Whi ch change 17. BIO 18. BID p rodu ced thi s effect: the w arming o f th e ai r o r the w a rmin g of the b ody o f the flut e? A fri end 's vo ice sound s d iffe re nt o ver th e t elephone t han it d oe s in p erson. Thi s is bec ause te le phon es d o not tran smit frequenci es o ver a bout 3 000 H z. 3 000 H z is well a bove t he normal fre quen cy o f s peec h, so w hy d oe s eli minat ing t hese hi gh frequencies change the s o und o f a p erson 's voice? S uppo se you w ere to pl aya t ru mp et a ner b rea th ing he lium, in which the speed o f s ound is muc h grcatcr than in air. W ould the pitc h o f t he in str um ent b e higher o r lower t han n orma l, o r w ou ld it b e u naffec ted by being pl aye d with hel ium i nside t he tube rather than air? I f you p our l iquid in a tall , narr ow g lass, y o u m ay hear s ound wi th a steadil y ri s ing pitch. W hat is the s o urce o f t he s ound , and why d oe s the pitch ri se as the glass ri ll s? W hen y ou s peak a fter b reathing he lium . in w hi ch the sp ee d of s ou nd is mu ch g reater th an in air, y ou r vo ice s ound s quite d iffere nt. T h e f requencie s emitted by y ou r vocal c ords d o not change since th ey a re d etermin ed by the m a ss and ten s ion o f y our vocal cords. S o w hat do es c hange whc n y our v ocal tract is filled w ith heli um rather than air? S oprano s c a n s i ng n otes a t v ery hi gh f requ e nc ies-over 1000 H z. W h en they s in g such high notes. it c a n be difficult to understand the words th ey a re s in g in g. Use t he c o ncepts o fh armonies and fo rmants to e x plain th is. W hen you h it a baseba ll w ith a bat. the bat n exes a nd th en vibrates. We can mode l th is v ibration as a tr an sve rse s tand ing w ave . T he m odes o f thi s standing w ave a re s imil ar to the mod es o f a s tretched s tring . b ut w ith o nc i mportant d ifference: T h e e nd s o f the bat are anti nodes instead o f n odes, because tbe e nds o f the bal are free 10 move. T he m odes thus loo k li ke the modes o f a stretc hed s trin g with anti nodes re placing nodes and nodes replac in g antinodes. If the ball hit s th e bat near an an ti node o f a standing-wave m ode, the bat will start osc illating in thi s m ode . T he baLter holds the bal at one end , wh ich is also an anlinode, so a large vibration o f the bat c a uses an unpleasant vibrat ion in the batter 's hands. Thi s c a n be avoided if the ball hits tbe bat at what pl ayers ca ll t he " sweet s pot," w hi ch is a node o f t he stand ingwave pattern. T he fi rst standin g-wave m ode o f a vibrat ing bat is the 111 = 2 m ode. Sketch th e appearance o f this vibrat ional mode o f the bat, the n e s timate the approx imate di stance o f t he s weet spot (as a fraction o f the bat's length) from the e nd o f the baL I f a c old g ives y o u a s tuffed-up nose. it changes the w ay y our vo ice s o unds, e ven i f y o ur vocal c ords a re not affected. Exp la in w hy t hi s is so. A s mall b o y a nd a g row n w oman b o th speak at a pproximate ly the s ame pitch. N onet he less, iI 'S e asy to te ll w hich is whi ch from li stening to the so unds o f their voices. How are you a ble to m ake thi s determi na ti on? 5 32 C HAPTER 16 S uperposition a nd S tanding W aves 19. Fig ure Q 16.1 9 sh ows w ave f ronts o f a circ ul ar wave. A re the di splace ments at t he following pairs o f p ositio ns i ll phase o r 0111 o f p hase ? E xplai n. a. A and B b. C a nd D c. E and F D o~ F B 0 EO A FIGURE Q16 .19 M ultiple-Choice Q uestions Q uestions 2 0 throu gh 22 refer to the s na pshot graph F igure Q 16.20. y (mm) 3 ') I' = + 6cm/s Snapshot graph at I = 0 S ~~ ~::~~'~-r-r'-~~~-rJI~,-,,~~20 x~m) I~ 5 ;'-r -t 5 10 -2 )' = - 6cm/s FtGURE Q16 .20 20. I At f = I s , what is th e displaceme nt y o f t he string at x = 7 e m? A. - 1.0 m m B. 0 m m C . O.S m m D. 1.0 mm E . 2 .0 mm 2 1. I At x = 3 e m, w hat is the e ar li es t time that y w ill e qua l 2 m m ? B. 0 .7, C. 1.0 , A. 0 .5s D. 1. 5 s E. 2.5 s 22. I A tf= I. Ss , what is th eval ueo f ya t x= 10 cm? A. - 2.0 m m B . - l. 0 m m C . - O.S m m D. O mm E . 1. 0mm 23 . II T wo s inu so idal w aves w ith the sa me a mplitude A a nd frequency f trave l in o ppos it e direc ti ons a long a l ong s tring . You stand at one point and watch the string. T he m a x imum d isplacement of the s t ri ng at that point is B. 2A C. 0 A. A D. T h ere is not enoug h information to decide. 24. I A stu den t in her p hy s ics lab meas ures t he st anding-wave m ode s of a tu be. T h e lowes t freque ncy th at m akes a r eso na nce is 2 0 H z. A s the frequency is in creased, the nex t reso nance is at 6 0 H z. W h at will be the next resonance after thi s? A. 80 Hz B. 100 Hz C. 120 Hz D. 180 Hz 2 S. I An o rga n p ipe is tun ed to e xac tl y 384 Hz when t he t emp erature in t he room is 200C. Late r, w hen th e air has w a rm ed up t o 2S oC, th e frequency is A. G reater than 384 Hz . B . 384 Hz. C . Less than 384 Hz. 26. II T wo guitar stri ngs made o f the s ame t yp e o f w ire have the same length. S tring I has a hi gher pitch than string 2. Which of the fo ll ow in g is tru e? A. T h e w ave s peed o f string 1 is g rea ter than that o f s tr in g 2. B. T h e tens ion in string 2 is g reater than th at in string I. e. T h e w aveleng th o f the l owe st s tanding-w ave m ode on string 2 is longer than that o n string 1. D. T h e w avele ngt h o f th e lowe st s tanding-wa ve m ode o n strin g 1 is longer than lhat on string 2. 27. I T he freq uency o f t he lowest standin g-wave m ode o n a I. O- mlong str in g is 2 0 H z. W hat is the w ave s peed o n the string? A. 10 m /s B. 20 mls C. 30 m /s D. 4 0 mls 28. I Suppose you pluck a string on a guitar and it produces th e note A at a frequency o f 4 40 H z. N ow y o u p ress your fi nger down o n the string aga in st one o f th e frets, making thi s p ointlh e new e nd o f th e string. T he new ly shortened string has 41S th e length of th e full string. When you pluck th e string, it s frequen cy w ill b e A. 350 Hz B. 440 Hz C. 490 Hz D. 550 Hz P ROBLEMS Section 16.1 T he Principle o f S uperposition I . I Figure P 16. 1 is a s na pshot gra ph at ( = 0 s o f t wo w aves o n a taut string a pproac hi ng e ac h oth er at 1 m /s. D raw s ix snapshot g rap hs, stacked vertically, showi ng the s tring at I s intervals fr om f = I s to I = 6 s. 2. II F igure P 16 .2 is a s naps hot g rap h at f = 0 s o f t wo w aves a pproachin g e ac h other at I m /s . D raw four s napshot graph s, stacked verticall y, s howing the string at I = 2, 4, 6, a nd 8 s. y (cm)atr = Os y (cm)att = Os j"-~~,\-~h~-,-''' X ( m) 2 FIGURE P16 .1 - t 4 6 8 10 FIGURE P16 .2 - 1 P roblems 3. II Fi gure P16. 3a is a s napshot graph at t = 0 s o f two waves o n a strin g approac hing e ac h other at At what tim e was the snapshot graph in F igure P 16.3b taken ? (, ) ( b) y (c m) a t' = O s ..v (c m) 'f--~--L~~...L,--l.~ x (m) 246810 ~ ~O x (m) l~ 0246810 FIGURE P 16.3 S ection 16.2 S tanding W aves S ection 16.3 S tanding W aves o n a S tring 4. III Fi gure P 16.4 is a s napshot graph at t = 0 5 o f a pul se on a string mov ing to the ri g ht at I m/s. The string is fixed at x = 5 m. D raw a hi story g raph spannin g the lime interval! = 0 s to ! = lO s for the locatio n x = 3 m on the string. y (c m )all = O s A F ixed end ~"'---:=--I-~-l-~-~_~~_~~--".c;....::o,f- x ( m) -] 2 3 4 5 -A FIGURE P 16 .4 5 . III At 1 = 0 s , a s mall '; upward " ( po s itive y ) pul se centered at x = 6 .0 m is mo ving to the ri ght on a s trin g with fixed ends at x = 0 .0 m and x = 10 .0 m. Th e wave speed on the strin g is 4 .0 m /s. At what time will the string next have the same a pp earance that it did at t = 0 s? 6. III Yo u are ho lding o ne e nd o f an e las ti c c o rd that is fastened to a wall 3.0 m aw ay. You b e g in s hakin g the e nd o f t he c o rd at 3.5 Hz, c reating a c o ntinuo us sinu soidal wave o f wave le ngth 1.0 m. H ow much time will pass until a standing w a ve fill s the entire length of the strin g? 7 . III A 2 .0-m-Io ng string is fixed at both e nd s and ti ghte ned until the wave speed is 4 0 m/s . W h at is the frequency o f the standing wave shown in Fi gure P I6 .7? 0 00000 C >C>C>L 6 0cm FIGURE P16 .7 FIGURE P 16 .8 S. II Fi gure P16. 8 shows a standing wave oscillating at 100 Hz on a strin g. What is the wave speed ? 9. II A b ass guitar string is 89 c m lon g with a fundam ental freque ncy o f 30 Hz. W hat is th e wave speed on this string? 10. III T he fund a mental frequency of a guitar string is 384 H z. W h at is the fundamental frequency i f the te ns ion in the strin g is halve d? 11. II a. W hat a r e the three longes t wavele ngth s for standing waves on a 240-cm-lon g strin g that is fi xed a t both e nds? b. I f the fre qu e ncy o f t he s ec ond - lon gest w ave length is 5 0.0 H z, what is the frequen cy o f th e third-longest wavele ngth ? 5 33 12. II A 121 -em -lon g, 4 .00 g string osc illates in its m = 3 mode with a fre qu ency o f I SO Hz a nd a m aximum a mplitude o f 5 .00 m m . What are (a) th e waveleng th a nd (b) the ten sion in the string ? 13. II A g uitar s tring with a linear dens it y o f 2.0 g / m is stretc hed betwee n supports that a re 6 0 c m apart. The string is o bse rved to form a standing wave with thr ee a ntinodes when dri ven at a frequ e ncy o f 420 Hz. W hat a r e (a) the freque ncy o f t he fifth harmonic o f thi s string and (b) the tension in the string ? 14 . II A violin string has a standard length of 32.8 cm. I t s ounds the mu sical note A (440 Hz) w hen p layed without fingerin g . How far from the e nd o f the string s hould you pl ace y our fin ger to play th e note C (523 Hz)? 15. II T he lowest note on a grand pi ano has a fr equency o f27 .5 H z. The entire string is 2 .00 m lo ng a nd h as a mass o f 4 00 g . The vibratin g secti o n o f the strin g is 1.90 m lon g. W hat ten s io n is needed to tune thi s strin g p roperly? S ection 1 6.4 S tanding S ound W aves 16. I The lowes t frequen cy in the audible range is 20 Hz. (a) W hat are the len gth s o f (a) the s hortes t open- open tube and (b) the short es t open-closed rube needed to produce thi s fre qu e ncy? 17. I The c ontrabassoo n is the wind instrument capable o f s ound ing the low es t pitch in an orches tra . It is folded over several tim es to fit it s impress ive 18 ft len gth into a reas onabl e s ize in strument. a. I f w e m odel th e in strume nt as an o pe n-clo sed tube . w hat is it s fundamental frequen cy? T h e s o und spee d in side is 350 m/s because the air is warmed by the pl ayer 's b reath. b. T h e actu al fundamental fr e qu ency o f th e c ontrab assoo n is 27.5 Hz, which should be d ifferent from your answer in part a. Thi s mean s the model o f tbe ins tr ument as an o pen-d osed tu be is a bit too s imple. But i f y ou ins ist on us ing th at m odel, what is th e " e ffec ti ve len gth" o f the in strument? 18. I Fi gure P I6 . IS s hows a f = 500 Hz s tanding sOllnd w a ve in an SO- cm-Ion g tube . T h e tube is fill ed with an unkn own g a s. 80 em W h at is the speed o f s ound in thi s gas? FIGURE P 16 . 18 19. II W hat a r e the thr ee lon ge st wave lengths for standin g s ound w aves in a 1 2l- cm-lon g tube that is (a) open at both e nd s a nd (b) o pen at o ne e nd , c losed at the other? 2 0. I The lowes t pedal note on a large pipe organ has a fundam ental frequency o f 16 Hz. Thi s extreme bass note is m ore fe lt a s a rumble than heard with the e ars. What is the leng th o f the openclosed pipe that mak es that note? 21. II T he fundamental frequency o f a n open-open tube is 1500 Hz INT whe n th e tube is fill ed with w e h elium. W h at is its freque ncy when fill ed with OD air? e 22. I Pa rasatlrolophu s w as a BID d in os aur w ho se di stin gui shing feature was a ho ll ow crest o n the head. The I.S -m-Io ng hol lo w tube in the c rest had connec ti o ns to the nose a nd t hroat , leadin g s om e in vestigato rs to hypoth es ize that the tube w a s a res onant c hamber for vocali zati o n. I f y ou model the tube as an o pen-cl osed system, what are the first three resonant frequencies? <:==:x:==:> 5 34 C HAPTER 16 S uperposition a nd S tanding W aves 23. II A d rainage pipe runnin g under a freeway is 3 0 .0 m long. Both ends of th e pipe are open, and wind blowing across o ne e nd c auses the air inside to vibrate. a. I f the speed o f sound on a particular day is 340 mis, what will be the fundamental freq uen cy o f air vibration in this pipe? b. What is the frequency of the lowest harmoni c that would be audible to the human ear? c. Wh at will happen to th e frequency in th e later afternoon as the air begins to cool? 24. Although the vocal tract is quite compl icated, we can make a BIO s imple mode l o f it as an open-closed tube ex tend in g from the opening o f the mouth to th e diaphragm, the large musc le separating the abdomen and th e chest cavity. What is th e length o f this tube if it s fundam ental frequency equals a typical speec h frequency o f 200 Hz? Assume a sound speed o f 3 50 m /s. Does this result for the tube length see m reasonable, based on observatio ns on your own body? 111 25. 1 A c hild ha s an e ar canal that is 1. 3 cm long. At what so und BIO frequencies in the audible range will the child have in creased hearing sensi ti vity? Section 16.5 Speech a nd H earing 26. I The fir st formant o f your vocal system can be modeled as the I BIO resonance o f a n open-closed tube, the closed end be in g yo ur vocal cords and the open e nd y our lips. Estimate the frequency o f the first formant from the graph o f Figure 16.23, and then estimate the length o f th e tube o f wh ich this is a resonance . Does your resu lt seem reasonable? II 27. I Deep-sea divers often breathe a mixture o f helium and oxyBIO ge n to avoid the c o mpli cat ions of breathing hi gh-pre ss ure INT nitroge n. At great depths the mi x is almost entirely helium, which has the side effec t o f making the divers' voices sound very odd. Breathing helium d oesn't affect th e frequency at which the vocal cords vibrate, but it does affect the frequencies o f th e formants. The text gives the frequencies o f (h e first two formants for an " ee" vowel sound as 270 and 2300 H z. What w iU these frequencies b e for a helium-oxygen mixture in w hich the speed o f sound at body temperature is 750 m/s? Section 16.6 T he I nterference of Waves from Two Sources 28. I Two loud speakers in a 20C room e mit6 86 Hz sound waves II along the x-ax is. What is the smallest distance between the speakers for which th e inte rfe rence o f the sound waves is destructive? II 29. I Two loudspeakers emit sound waves along the x-axis. The sound has maximum inte nsity when th e speakers are 2 0 cm apart. The sou nd intensity decreases as the distance between th e speakers is increased, reachin g zero at a separation o f 30 cm. a. What is th e wavelength o f th e sound? b. If the distance between th e spea kers continues to increase, at what separation will the sound inte nsity again be a maximum ? 111 30. 1 id Two enti cal loud speakers separated by distance d emit 170 Hz so und waves along the x-ax is. As you walk along the axis , away from th e speakers, you d on't hear anything even though both speakers are on. What are three possible va lues for d? Assume a sound speed o f 3 40 m /s. 3 1. I F igure P 16. 3 1 shows the c ircular wave fronts emitted by two source s. M ake a table with rows labeled P, Q , and R and col umn s labeled I" l, 1"2 , 6.r, and C /D. Fill in the labl e for points P, Q, and R, g iving the di stances as multi ples o f A and indi cat in g, with a C or a 0 , whether (h e interference at that point is construct iv e FIGURE P16.3 1 or destructive. 32. III Two identical loudspeakers 2.0 m apart are emitting 1800 Hz so und waves into a room where th e speed o f sound is 340 m/s . Is th e point 4.0 m directly in front o f one o f the speakers. perpendicular to the plane o f the sp ea kers, a point o f maximum constructive inte rference, perfect destructive interference, or something in between? Section 16.7 Beats 33. I Two s trin gs are adjusted to v ibrate at exactly 200 H z. Then th e tension in one str in g is in creased s li ghtly. Afterward, three beats per second are heard when the st rin gs vibrate at the sa me time . What is the new frequ e ncy o f the strin g that was ti ghtened? 34. II A flute player bears four beats per second when she c o mpares her note to a 523 Hz tuning fork (the note C) . S he can matc h the frequency o f the tuning fork by pulling out th e ';tu nin g jo int" t o l engthen b er flute s li ghtl y. What was her initial fr eq uency? G eneral P roblems 35. I The fundamental frequency o f a stand in g wave on a 1.0-111long string is 4 40 Hz. What would be the wave speed o f a pu lse moving along thi s string? 36. II I In addition to prod uc in g im ages, ultrasound can be used to BIO heat ti ssues o f th e body for therapeutic purposes. When a sound INT wave hits the boundary between s oft tissue an d a ir, or between so ft ti ssue and bone, most o f the energy is reflected; only 0.11 % is transm itte d. T his means that standin g waves can be set up in the body, creating excess thermal e ne rgy in the ti ssues at an antinode. Suppose 0.75 MHz ultrasound is directed through a layer o f ti ssue with a bone 0.50 c m below th e surface. Will stand ing waves be created? Explain. 37. III An 80-c m-long steel string with a linear density o f 1.0 g /m is INT under 200 N tension. I t is plucked and vibrates at it s fundamen tal frequency. What is th e wavelength o f the sound wave that reaches your ear in a 20C room? 38. 1111 Tendons are, essentiall y, e last ic cords st retched between BlO t wo fixed en ds; as such, th ey c an suppo rt standin g waves. INT T hese re sonances can be undesirabl e. Th e Achilles tendon connects th e heel with a muscle in the calf. A woman has a 20c m-Iong tendon with a cross-sec tion area o f 110 mm 2 . T he d ensity o f tendo n ti ss ue is 1100 kg/ m 3 F or a reasona bl e tension o f 5 00 N, what will be the resonan t frequen c ies o f h er Achilles tendon? 39. I A strin g, stretched between two tixed posts, forms standin gwave resonances at 325 Hz and 390 Hz. What is the largest po ssible val ue of it s fundamental frequency? P roblems 40. 1 S p iders may "t un e" s tra nds o f th e ir webs to give enhanced 111 BID re sponse at frequ enc ies corresponding to the frequencies at w hi ch INT desirable prey mi ght s tru ggle. Orb web silk has a ty pi cal diameter of 0.0020 mm , and spider silk has a dens ity of 1300 kg/mJ . To g ive a reso nance at 100 Hz, to what tension mu st a spider adjust a l2 -c m-long strand o f s il k? 4 1. III A viol ini st places her fin ger so th at th e vibrat ing s ecti on o f a !NT 1.0 g/m strin g has a le ngth of 30 cm, then she draws her bow across it. A li ste ner nearby in a 2 0 D C room hears a note wi th a waveleng th o f 4 0 e m. What is the ten sion in th e strin g? 42. II A partic ular ly beautiful note reac hin g your e a r from a rare INT Stradivarius violin has a wavelength of 39. 1 c m. The room is s li ghtly warm, so the speed o f sound is 344 m/s. I f the strin g's linear de nsity is 0.600 g/m a nd th e tensio n is 150 N, how long is th e v ib ra tin g section o f the violin str in g? 4 3. II A heavy pi ece of hang in g sculpture is suspended by a 90-cmINT lo ng, 5.0 g stee l wire. When th e wind blows hard, the wire hums at it s fundam e nt al frequency o f 8 0 Hz. Wh at is th e mass o f the sculpture? 44. I An exper im e nter finds that standin g waves o n a 0.80- m-long str in g, fix ed at both ends, occ ur a t 24 Hz and 32 Hz, but at no freq uencies in between. a. What is th e fundam e ntal freque ncy? b. What is the wave speed on th e string? c. Draw the stand in g-wave patte rn for the str in g at 32 Hz. 45. III Astrona ut s visitin g Planet X have a 2.5-m-long string whose INT m ass is 5.0 g. T h ey tic the string 10 a s upport , streIc h it hor izo nt ally over a pull ey 2.0 m away, a nd h ang a 1.0 kg mass on the fr ee end. Then the astronauts beg in to exc ite standin g waves o n the str in g. Their data show that standin g waves ex ist at fr eq ue ncies of 64 Hz an d 8 0 H z, but al no frequenc ies in betwee n. Wh at is th e va lu e o f g, th e free- fall acce lerati o n, on Planet X? 46. 1111 A 75 g bungee cord has a n eq uilibrium length o f 1.2 m. The INT c o rd is stretched to a lengt h o f 1. 8 m, then vibrated at 20 H z. Thi s produces a stand in g wave with two anti nodes. What is th e sprin g constant o f th e bu ngee c o rd? 47. 11111 A 2 .5-c m- diameter steel c a bl e ( with density 7900 kg/m3) that is part of th e suspensio n syste m fo r a footbridge stre tches 14 m betwee n th e tower and th e gro un d. After walkin g ove r th e bridge, a hiker finds th at th e c a bl e is vibrat ing in its fundamental mode with a period o f OAO s . What is th e te nsio n in the ca bl e? Ay( m) 48. Jl Lake E ri e is prone to 060 b ~ x (km) remarka bl e seiche,'i-s tan ding o -C)() 400 waves that slosh water back - 0.60 Toledo Buffalo and forth in th e lake basin from th e west end at Toledo to th e FIGURE P1S .48 e as t end at Buffalo. Figure P I6A 8 s ho ws smoothed data for the di spl ace ment fr om normal water leve ls a long th e lake at the hi gh point of one part icu lar se iche. 3 ho urs laler th e water was at normal levels throughout the bas in ; 6 ho urs late r th e water was hi gh in Toledo and low in Buffalo. a. What is th e wavelength o f thi s standin g wave? b. What is the fr eq uency? c. What is th e wave speed? r------...,.".-..., 5 35 Steel wire Pull 49. II I A stee l w ire is used to ~ INT stretc h a sprin g, as shown in S pring Figure P16A9. An osc ill at in g magne ti c fi e ld d ri ves the stee l FIGURE P1S .49 wi re back and forth . A stand in g wave with three an ti nodes is created when the sprin g is stretched 8.0 cm. What stretch o f th e sprin g produces a standi ng wave with two antinodes? 50. II J ust as you are about to step into a nice hot bath, a small e arth quake rallies your bathroo m. Immediately afterward , you not ice that the water in th e tub is osc ill at in g. Th e water in the ce nter seems to be mo ti o nl ess w hi le the wa ter at the two ends a lt ernate ly ri ses a nd fa ll s, like a seesa w. You happe n to kn ow th at your bathtub is 1.4 m long, an d yo u c o unl 10 c o mplete oscill ati ons o f the water in 20 s. a . What is the wavele ngth o f t hi s standing wave? b. W hat is th e speed of the waves that are reflec tin g back and forth in side the tub to create th e standing wave? 5 1. II I A mic rowave generator ca n IDem prod uce mi crowaves at any fr eq ue ncy between 10 GHz and Mi crowaves " --- - - - ---" 20 G H z. A s Figure P16.51 s hows, th e mi crowaves are FIGURE P1S . Sl a im ed, through a sma U ho le, into a " mi crowave cav ity " th at con sists of a 1O-c m-Io ng c y li nde r with re fl ec ti ve end s. a. Which fr equenc ies between 10 G H z and 20 GH z w ill create standi ng waves in the mi crowave cav ity? b. F or w hi c h of th ese fr eque nc ies is th e cav it y midpoint an a nti node? 52. An open-open organ pipe is 78.0 c m lo ng. An o pen-closed p ipe has a fundamental fr equency e qual 10 the third harmonic o f th e ope n-open pipe. How long is th e open-closed pipe? 53. II I A carbo n-dioxide lase r e m its infrared ti ght with a wavelength INT o f 10.6 .urn. a . What is th e length of a tube th at will osc ill ate in the 111 = 100,000 mod e? b. What is th e freque ncy? c. Im ag in e a pul se o f li g ht bounc in g back and forth betwee n th e ends o f the tube. How many round trips will the pul se make in each second? 54. II I In 1866, th e G er man sc ienti st Adolph Kundt develo ped a tec hnique for accurately measuring th e speed of sou nd in va rio us gases. A lon g glass tube, kno wn today as a Kundt 's tube, has a vibrat in g pi sto n at o ne end and is c lo sed at th e other. Very finely gro und parti cles of cork are sprinkl ed in the bottom of th e tube be fore th e pi ston is inserted. As th e vibratin g pi ston is slow ly mov ed forward, there are a few position s that cause th e cork particles to c o Uecl in s mall , regularly spaced piles along th e bottom. Fi gure P1 6.54 shows an ex per im ent in w hi ch th e tube is filled with pure oxyge n and th e pi ston is dri ven at 400 H z. fIJ\J\r: Piston Glass lUbe Piles o f cork particles I FIGURE P1S.54 123 e m a. Do th e cork parti cles c o ll ect at standin g-wave nodes or a nti nodes? H int: Co ns ider th e appearance o f th e ends o f the tub e. b. What is the speed o f s ound in oxygen ? 5 36 C HAPTER 16 S uperposition a nd S tanding W aves 55. II A 4 0-cm-long tube has a 40-cm40 em lo ng in se rt that can be puUed in and ~ out, as shown in Figure PI6.55. A -----e==~== 4 0cm vibratin g tunin g fork is held next to ----L.,--~ the tube. As the in sert is slow ly pulled out, the sound from the tun- FIGURE P16 .55 ing fork creates standin g waves in the tube when the total leng th L i s 42.5 cm, 56.7 cm, and 70.9 cm. What is the frequency of the tuning fork? The a ir temperature is 20C. 56. 1 A 1.0 -m-ta ll vertical tube is filled with 20C water. A tuning 111 fork vibrating at 5 80 Hz is held just over the top o f the tube as the water is slowly drained from the bottom. At what water he ig ht s, measured from the bottom of the tube, will there be a standin g sou nd wave in the a ir at the top o f the tube? 57. II A 50-cm- lon g w ire with a mass o f 1.0 g and a ten sion o f 4 40 N passes across th e open end o f an open-closed tube o f air. T he wire, which is fixed at both ends, is bowed at th e center so as to vibrate at its fundamental frequency and generate a sou nd wave. Then th e tube len gth is adjusted until the fundam e ntal frequency o f the tube is heard. What is th e lengt h o f the tube? Assume the speed o f sou nd is 340 m /s. 58. III A 25-cm- lon g wire with a linear density o f 20 g/m passes across the open e nd o f an 85-cm-long open-closed tube o f air. If the wire , w hi ch is fixed at both ends, vibrates at it s fundamental frequency, th e sound wave it generates exc ites th e seco nd v ibrational mode o f the tube o f air. What is the tension in the wire? Assume the speed o f sou nd is 3 40 m /s. 59. I Two loudspeakers located II along the x-axis as shown in Figure P 16.59 produce sounds o f equal frequency. Speaker 1 is at the origin, whil e the loca tion o f FIGURE P16 .59 speaker 2 c a n be varied by a remote c o ntrol wielded by th e li sten e r. He noti ces maxima in the sound intens ity when speaker 2 is located at x = 0.75 m a nd 1.00 m, but at no points in betw ee n. W hat is the frequ ency o f the sound? Assume the speed o f sound is 340 m /s. 60. I You a re standin g 2.50 m directly in front of o ne o f the two II loudspeakers shown in Fi g ure P16.60. Th ey are 3.00 m apart and both are playing a 686 Hz tone in phase. As you begin to w alk directly away fr om the speake r, at what distances from th e speaker do you hear a minim/lm sound intensity? The room temperature is 20e. - 62. 63. 64. Bl0 65. W alk 2 .50m 66. 3.00m FIGURE P16 .60 61. II FM sta tion KCOM ("All c o mmerc ial s, all the time") transmits sim ultaneously, at a frequency o f 9 9.9 MHz, from two broadcast towers placed preci sely 3 1.5 m apart along a north south line. a. What is the wavelength o f K COM's transmissions? 67. b. S uppose you stand 90.0 m due eas t o f the point haJfway between th e two towers with your portable FM radio. Will you re ce ive a s trong o r weak sig nal at thi s position? Why? c. You then stand 90.0 m due north o f the northe rn tower with your radio. Will you receive a strong or weak signal at this position? Why? II I Two loudspeakers, 4.0 m apart and facing each other, play id e nti cal so und s o f the same frequency. You stand halfway between them, where th ere is a maximum o f sou nd inte nsit y. Moving from this point toward one o f the spea kers, yo u encoun ter a minimum o f sound intensity when you ha ve moved 0.25 m. a . What is the frequency o f the sou nd ? b. If the freq ue ncy is then increased while you re main 0.25 m from the center, what is the first frequency for which that location will be a maximum o f sound intens ity ? 1111 Two radio antennas are separated by 2.0 m. Both broadcast iden ti cal 750 MHz waves. If you w alk around the antennas in a c ircle o f radius 10 m, how many maxima will you detect? I Certain birds produce vocalizations c o nsistin g o f two distinct frequencies that are not harmonically r elated-that is, th e two fr equencies are not harmoni cs o f a c ommon fundamental frequency. These two frequencies mu st be produced by two differe nt v ibrating stru ct ures in th e b ird's vocal tract. a. Wood ducks have been observed to make a call with approximately equal inten sities at 850 Hz and 1200 H z. T he membranes that produce the vocal izations do not seem to vibrate at frequencies le ss tban 500 Hz. Given this limitation, could these two frequencies be higher harm o ni cs o f a lowerfrequency fundamental ? b. If we model th e duck's vocal tract as an o pen-closed tube, what len gth has a fundam ental freq ue)l cy eq ual to the lower o f the two fr eq uenc ie s in p art a? Pi ano tuners tune pianos by listening to th e beats between th e harmoni cs o f t wo different strin gs. When properly tuned, th e note A should have the frequency 440 Hz and the note E should be at 659 Hz. T he tuner ca n determine thi s by li stenin g 10 th e beats between the third harmonic o f the A and th e second harmonic o f the E. a. A tuner first tunes th e A string very precisely by matching it to a 440 Hz tuning fork. S he th en strikes the A and E str in gs simultan eo us ly and li stens for beats betw ee n th e harmonics. What beat fr equency indicates that th e E str in g is properly tuned? b. T he tuner starts with th e tens io n in th e E string a little low, th en tightens it. What is the frequ ency o f the E str in g when she hears four beats per second? II I A fluti st asse mbles her flute in a room where the speed o f sou nd is 342 m /s. When she plays the note A, it is in perfect tune with a 440 Hz tuning fork. After a few minutes, the air in s id e her flute has warmed to where th e speed o f sou nd is 346 m /s. a. How many beats per seco nd will she hear if she now plays the note A as the tuning fork is sou nded? b. How far does she need to e xtend th e "tuning j oint" o f her flute 10 be in tune with the tuning fork ? II I A student waiting at a s topli g ht notices that her turn sig nal , which ha~ a period o f 0.85 s. makes one blink exactly in sync w ith th e turn sig nal o f the car in front o f he r. T he blinker o f the car ahead th en statts to get ahead, but 17 s later the two are exactly in sy nc aga in. What is th e period o f the blinker o f the other car? P roblems 68. III Mu sicians can use beats to tune th e ir in struments. One nute is properl y tuned and pl ays the mu sica l note A at exactly 440 H z. A second player sound s th e same no te and hears that her in strume nt is s li ghtly " nat " ( i. e., at too I owa frequ ency). Playing at the sa me time as the first flut e, s he hears two loud -so ft loud bea ts per seco nd. Mu st she short en or le ng th en her flut e, an d by how mu ch, to bring it in to tune ? As s um e a speed o f sound o f 350 m /s . 69. II I Poli ce radars determine speed by measurin g th e Doppl er INT s hift o f radio waves re nected by a mov in g ve hicl e. They do so by determining the beat fr eque ncy between the re fl ected wave and the 10.5 GH z emitted wave. Some units can be calibrated by us in g a tuning'fork; holding a vibratin g fork in front of the unit causes the di splay t o reg ister a speed correspon ding to th e vibrat ion frequency. A tuning fork is label ed "55 mph ." What is the fr equency of the tuning fork ? 70. II A Doppl er blood flow meter emits ultrasound at a frequency BIO o f 5 .0 MH z. What is the bea t frequency betwee n th e em itted INT waves and the waves reflected from blood c e ll s mov in g away from the emitter at 0.15 m l s? 71. I An ultraso und unit is being used to meas ur e a patient's heart BIO beat by combining th e emitted 2.0 MH z sig nal with the so und INT waves re fl ec ted from the mov in g ti ssue o f one point on tb e hear t. The beat frequ ency between the two signals ha s a max imum value o f 520 Hz. What is the maximum speed of th e heart ti ss ue? 5 37 o r very close to each other (w ithin a few Hz). Thi s is the key to consonance: harmonics that are spaced e ith er far apart or very close. Th e close harmonic s have a beat Frequ ency o f a few Hz that is pe rc eived as pl easant. I f the harmon ics of two notes are close but not too close, th e rathe r hi gh beat freq ue nc y between the two is quite unpleasan t. Thi s is what we hear as di ssonance. Ex ac li y how mu c h a difference is ma ximally di ssonant is a matter of opinion, but harmoni c separati ons o f 30 or 40 Hz seem to be quite unpleasant for most peo pl e. 1568 - - i ~ ,t - - - 1572 - - - 1310 1176 - - - - 1048 784 - - - - - 786 - - - 524 392 - - - - 262 Hannonics FIGURE P16 .72 Hannonics oro orc You kn ow that ce rtain mu sic al notes sound good togethe rharmoni ous-w hereas others do not. Thi s harmon y is related to the various harmo ni cs o f th e note s. The musica l notes C (262 Hz) and G (392 Hz) m ake a pl easant so und when pl ayed togeth er; we ca ll thi s consonance. As Fi g ure P I6 .72 s hows, th e harmonics o f the two notes are either far from each other 72. I What is the beat frequency betwee n the second harmoni c o f G and the third harmon ic o f C ? A. I H z B. 2 H z C 4 Hz D. 6 H z 73. I Would a G-flat ( fr equency 370 Hz) and a C played to gether be c onsonant o r di ss onant? A. Consonant B. Di ssona nt 74. I An organ pipe open at both e nd s is tuned so that it s fundamental frequen cy is a G. How long is th e pipe? A. 43 e m B. 87 c m C. 130 cm D. 17 3 em 75. I If th e C were played on an o rg an pipe that was open at one end and closed at th e other, which of the harmo ni c frequ enc ie s in F igure 16.72 would be present ? A. All o f th e harmo ni cs in the fi g ur e would be prese nt. B. 2 62,786, and 13 10 H z C. 524, 1048, and 1572 H z D. 262, 524, and 1048 Hz S top to T hink 16_ C. Th e fi g ur e shows th e two waves at 1 = 6 s 1: a nd their superpos ition. The s up erpos iti on is the point-by- point add ition o f th e di splaceme nt s of the two indi vidual wave s. f undam e ntal frequency. Beca use the difference between them is 100 H z, we see that 13 = 3 X 100 Hz and h = 4 X 100 Hz. T hu s I, ~ 100 Hz. ~~~~-4t:i7:\y; '-''-".-\-~~~~ x (m) .:c,- ' S top to T hink 16.4: D. Hi ghest pitch, or highest fr eq uency, corresponds to the shortest period. For a compl ex wave, the period is the tim e required for th e entire wave pattern to repea t. Passage P roblems H armonics a nd H armony o 24 6 8 10 12 14 16 18 20 S top to T hink 16.2: C. Standing-wave fr equenc ies are!,,, = mfl. The original wave has frequen cy 12 = 2 /1 because it has two anl inodes. The wave with frequ ency 2 /2 = 4 /1 is the m = 4 mode with fo ur a nti nodes. S top t o T hink 16.3: B. 3 00 Hz and 4 00 Hz are nol I, an d I , b ecause 400 Hz 2 X 300 Hz. In stead, both are multipl es o f the *" S top to T hink 16.5: C onstructive i nterference. The path -length difference is 6.r = 1.0 m = A. Inlerferen ce is construc ti ve when the path-le ngth difference is a wh ole number of wavelengths. S top to T hink 16.6: F. The beat Freq uency is th e difference between the two fr equenc ie s.

Find millions of documents on Course Hero - Study Guides, Lecture Notes, Reference Materials, Practice Exams and more. Course Hero has millions of course specific materials providing students with the best way to expand their education.

Below is a small sample set of documents:

SUNY Stony Brook - PHY - 142
SUNY Stony Brook - PHY - 142
SUNY Stony Brook - PHY - 142
14 OscillationsThis loudspeaker cone generatessound waves by oscillating backand forth at audio frequencies. Looking Ahead The goal of Chapter 14 is to understand systems that oscillate with simple harmonic motion.Simple Harmonic MotionSpringsPendu
UNC - ANTH - 145
ANTH145ObjectivesExam1Whyisstudyingworldprehistoryimportant?IntellectualCuriosityAnsweringquestionsaboutourpastTheLost100,000YearsArchaeologyfillsintheblanksDevelopmentofSocietyUnderstandhowsocietyworks/developedPopulationgrowthHyperstratificati
UNC - HIST - 292
Price 1Michael Ian Price720002165HIST 292-001Klaus LarresHow did Friedmans monetarist policy affect the growth of Britain and the United Stateseconomies during the Thatcher and Reagan administrations?Price 2In the second half of the twentieth cent
UNC - HIST - 292
Price 1Reading Journal 11/8Michael Ian Price, HIST 292-001After the coalition of Britain and the United States had satisfactorily eliminated the AlQueda and their Taliban protectors in Afghanistan, the immediate question was obvious. Whatnow? Blair h
UNC - HIST - 292
Ian Price720002165Smith, Geoffrey. Reagan and Thatcher. New York: W.W. Norton, 1991. Print.Lejeune, Anthony. Reagan &amp; Thatcher: The Balance Sheet. National review (New York) 40.9 13May 1988: 36. National Review, etc. 23 Oct 2012.Green, F., (1986 Wint
UNC - HIST - 292
Price 1720002165Michael Ian PriceHIST 292-001Britain in World Affairs: British Foreign Policy from 1945 to the PresentProf. Klaus LarresExamine the British response to both the nationalist independence movement in the Gold Coastand the Unilateral D
UNC - HIST - 292
Michael Ian Price720002165Reading Journal 7This reading journal focuses on the Margaret Thatcher, her domestic politics, and theimportance of the Falklands conflict. Generally speaking, Thatcher focused on modifyingeconomic and social policies in ord
UNC - HIST - 292
Michael Ian Price720002165Reading Journal 6The readings this week focused on Indias independence from Britain and its prior role as thejewel in the crown of Britains colonial holdings and Britains involvement in Palestine.After doing these readings,
UNC - HIST - 292
Michael Ian Price720002165Reading Journal 5My readings this week consisted of parts of three books: two that concerned the rise andfall of the British empire and the circumstances in which the empire existed, and the third focusedon exposing the natu
UNC - HIST - 292
Michael Ian Price720002165Readings:Klaus Larres, Introduction: Uneasy Allies or Genuine Partners? Britain, Germany, andEuropean Integration, in Klaus Larres with E. Meehan (ed.), Uneasy Allies:British-German Relations and European Integration since 1
UNC - HIST - 292
Michael Ian Price720002165This week I chose to examine Anthony Edens political life before the Suez Crisis in article 1,Edens role in the Suez Crisis and the factors from his past that caused his folly in article 2, andBritains role in the Suez Crisis
UNC - HIST - 292
Price 1720002165Michael Ian PriceHIST 292-001 (Larres)Britain in World Affairs: British Foreign Policy from 1945 to the PresentReview of British Social Policy since 1945Bibliographic Information:Glennerster, Howard. British Social Policy Since 1945
UNC - HIST - 292
Ian Price7200021651) British Social Policy since 1945 Howard Glennerster (p. 1-16)Within this book, Glennerster strives to describe and comment on the socialpolicies implemented by the British government from 1945 onwards. The first fewchapters focus
UNC - HIST - 292
Michael Ian Price7200021651) Transition of Power: Britain's Loss of Global Pre-eminence to the United States, 19301945;Brian J. C. McKercher (pp. 308-343)The Second World War brought about major changes in the dynamics of world politics.In 1940, as G
Old Dominion - COMM - 260
01/17/2012Hypertext and free speech-Who should have the right to insert a link that takes a user elsewhere?-Federal court found links to be both expressive and functional.-Courts found that hyperlinks are a form of free speech-Illegal downloading sof
Old Dominion - COMM - 260
April 5, 2012Fear and (self) loathing What are the dominant signifiers of masculinity in western society?o Strengtho Actiono Sexually assertiveo In control ( of their feelings) Since men are taught at an early age to act like a man and acting like
Old Dominion - COMM - 260
March 29, 2012 &amp; April 3KillingUsSoftly3(JeanKilbourne,2000)Advertisingroutinely:ReinforcesthenotionthatwomenshouldbeobsessedwithhowtheylookConstructsunattainableimagesofidealfemalebeauty&amp;suggestthatwomenare nottryinghardenoughtoattainthisstatusThou
Old Dominion - COMM - 260
March 27, 2012Analyzing gendered representations What does it mean to act like a lady or man upo Be more composed or be more brave Sex vs gendero Sex biological differenceso Gender refers to traits, behaviors we associate with men and women Biologi
Old Dominion - COMM - 260
Exam: Readings from 1/10 to 1/31New distribution strategies for a Post-network Era Video on demand, downloading, broadband: new materials available anytimewithout need of TVItemized economy; primary unit of exchange no longer thecd, dvd, or newspaper
U. Houston - ECON - 4368
4 Arbitrage and Spot Exchange RatesArbitrage - a trading strategy that exploits any profit opportunities arising fromprice differences: buy low and sell high.If such profit opportunities exist in a market, then it is considered to be outof equilibrium
U. Houston - ECON - 4368
Key PointsChapter 2:1.The exchange rate in a country is the price of a unit of foreign currency expressedin terms of the home currency. This price is determined in the spot market forforeign exchange.2.When the home exchange rate rises, less foreig
U. Houston - ECON - 4368
Chapter 31.Purchasing power parity (PPP) implies that the exchange rate should equal therelative price level in the two countries, and the real exchange rate should equal2.Evidence for PPP is weak in the short run but more favorable in the long run.
U. Houston - ECON - 4368
Chapter 41.Our theory of exchange rates builds on two ideas: arbitrage andexpectations. First, we developed the theory for the case of floating exchange rates.2.In the short run, we assume prices are sticky and the asset approach toexchange rates is
U. Houston - ECON - 4368
Cross Rates and Vehicle Currencies160 distinct currencies in the worldMostly traded currencies: dollar, euro, yen or poundvehicle currency - not the home currency of either of the parties involved in thetrade and is just used for intermediation.There
U. Houston - ECON - 4368
Effective Exchange Rates:Change in the Value of the U.S. Dollar, 20022010 The chart shows the value of thedollar measured by the U.S. Federal Reserve using two different baskets of foreigncurrencies, starting with the index set to 100 in January 2002.
U. Houston - ECON - 4368
IntroductionMonetary economics?- exchange rates, prices, interest rates, income, wealth, and the current account.International?- interconnections among nations are fully considered.Three key elements:The world has many monies (not one)Countries are
U. Houston - ECON - 4368
1 Exchange Rate EssentialsAn exchange rate (E) - price of some foreign currency expressed in terms of ahome (or domestic) currency.It may be quoted in either of two ways:1. The number of home currency units that can be exchanged for one unit offoreig
U. Houston - ECON - 4368
2 Globalization of Finance: Debts and DeficitsFinancial globalization has taken hold around the world, starting in the economicallyadvanced countries and spreading to many emerging market countries.Deficits and Surpluses: The Balance of Paymentsincome
U. Houston - ECON - 4368
3 Government and Institutions: Policies and PerformanceGovernment actions very important:- decisions about exchange rates, macroeconomic policies, whether to pay (or not pay) theirdebts, and so on.Economists studypoliciesregimes in which policy choi
U. Houston - ECON - 4368
Private ActorsThe key actors in the forex market are the traders.commercial banks: Interbank trading is highly concentrated: about three-quartersof all forex market transactions globally are handled by just ten banks.corporationsnonbank financial ins
U. Houston - ECON - 4368
Transaction CostsThe difference between the buy at and sell for prices is called the spread.Spreads are an important example of market frictions or transaction costs.The difference between the buy at and sell for prices is called the spread.Spreads ar
U. Houston - PHYS - 1322
Chapter 18 Electric Forces and Electric FieldsChapter 18ELECTRIC FORCES AND ELECTRIC FIELDSPREVIEWElectric charge is the fundamental quantity that underlies all electrical phenomena. Thereare two types of charges, positive and negative, and like char
U. Houston - PHYS - 1322
Chapter 12TEMPERATURE AND HEATPREVIEWThe total internal energy of the molecules of a substance is called thermal energy. Thetemperature of a substance is a measure of the average kinetic energy of the molecules inthe substance, and gives an indicatio
U. Houston - ECON - 3332
Chapter TwoDemand and Supply AnalysisChapter Two Overview1. Motivation U.S. dot coms2. Competitive Markets Defined3. The Market Demand Curve4. The Market Supply Curve5. Equilibrium6.Characterizing Demand and Supply Elasticity7.Back of the Envel
U. Houston - ECON - 3332
Constant Elasticity vs. Linear Demand CurvePrice Elasticity and CarsDurable GoodsThe Durable Good is a good that provides valuable services over a long time (usuallymany years).Demand for non-durables is less elastic in the short run when consumers c
U. Houston - ECON - 3332
Elasticities &amp; the Cola WarsEstimating Demand &amp; SupplyEstimating Demand &amp; SupplyFrom Past Shifts
U. Houston - ECON - 3332
Exogenous &amp; Endogenous VariablesVariables that have values taken as given in the analysis are exogenousvariables. Variables that have values determined as a result of themodels workings are endogenous variables.How would a manager hire the most possib
U. Houston - ECON - 3332
Identifying DemandBy a Shift in SupplyThis technique only works if one or the other of the curves stays constant. Identifyingdemand when both curves shiftChapter ThreeConsumer Preferences and the Concept of Utility1. Motivation2. Consumer Preferenc
U. Houston - ECON - 3332
Microeconomic Modeling Choice vs. Alternatives Models are like maps using visual methods, they simply the processand facilitate understanding of complex concepts. Microeconomic modelsneed to:Resemble RealityBe UnderstandableBe an Appropriate Scale
U. Houston - ECON - 3332
MicroeconomicsDavid Besanko &amp;Ronald R. Braeutigam3rd EditionAnalyzing Economic ProblemsMicroeconomics DefinedMicroeconomics is the study of the economic behavior of individualeconomic decision-makers such as consumers, workers, firms ormanagers. T
U. Houston - ECON - 3332
Price ElasticityElasticity is not slopeSlope is the ratio of absolute changes in quantity and price. (= Q/ P).Elasticity is the ratio of relative (or percentage) changes in quantity and price.Grocery Products ElasticityWhen a one percent change in pr
U. Houston - ECON - 3332
The Law of SupplyThe Law of Supply states that the quantity of a good offeredincreases when the price of this good increases. If the change increases the willingness of producers to offer thegood at the same price- the supply curve shifts right If t
U. Houston - ECON - 3332
The Market Demand FunctionThe Market Demand Function tells us how the quantity of a gooddemanded by the sum of all consumers in the market depends onvarious factors.Demand CurvesThe Demand Curve plots the aggregate quantity of a good thatconsumers a
TN Tech - EXPW - 2150
EXPW 2150Chap 3Jared Female Sexual Anatomy and Physiology Gynecology The medical practice specialization in womens health and in diseases of the femalereproductive and sexual organs It is crucial for a woman to have yearly examinations by either a
TN Tech - EXPW - 2150
EXPW 2150Chap 4Jared Male Sexual Anatomy and Physiology The Penis The Penis: Male sexual organ consisting of the internal root and the external shaftand glans Refer to figure 4.1 in your book, pg 89 Consists of nerves, blood vessels, fibrous tissu
Rutgers - MANAGEMENT - 33:620:430
Rutgers - MANAGEMENT - 33:620:430
Study Guide for Quiz 1Week 2 Effectiveness: Task Interdependence: Pooled- work independently then combine. Sequentialassembly line. Reciprocal- everyone is dependent on each other at every level.Models of team effectiveness: Discipline- common purpose,
Rutgers - MANAGEMENT - 33:620:430
Study Guide for Quiz 2Week 5 Diversity: Surface level- physical features. Deep level- attitudes, opinions. Faultiness- formationof sub groups. only occur in medium level diverse teams. Paradox of Diversity- diversity can producelower productivity and e
Kentucky - ACC - 324
Exam 3Chapter 10:- The Order Entry Sales Process (OE/S): reflects an interacting structure of people,equipment, activities, and controls that is designed to achieve certain goals.o The primary function of the OE/S process is to create information flow
UC Davis - ARE - 18
McCall and Teresa enter into a contract for the distribution ofb. an assignment.McCall's produce to local restaurants for which Teresa agrees to pay.McCall transfers his right to payment under the contract to MidtownBank. This transfer isa. a delegat
UC Davis - ARE - 18
Dwayne and Ewell enter into a contract for the design of an addition to b. anDwayne's house for which he agrees to pay Ewell. Ewell transfers his assignee.right to payment under the contract to Flex Construction Company. Flexisa. a delegatee.b. an as
UC Davis - ARE - 18
Trudy and Uri enter into a contract for the sale of Trudy's house for a. cannot bewhich Uri agrees to pay her $250,000. Uri wants to transfer his right prohibited.to the ownership of the house to Val, his niece. This transfer generallya. cannot be proh
UC Davis - ARE - 18
Miley and Rico enter into a contract for the closing of a sale ofMiley's recording studio. When Rico's schedule conflicts, he asksOliver to perform his duties at the closing. This transfer of duties isa. a delegation.a. a delegation.b. an assignment.
UC Davis - ARE - 18
Parsley, a world-famous chef, signs a contract to give lessonsin French cooking to Curry. Parsley wants to transfer hisduties under the contract to Relish, the operator of a hot dogconcession. The transfer isc. not valid becauseperformance dependson
UC Davis - ARE - 18
Joy and Kris enter into a contract for Kris to lay sod in Joy'syard for which she agrees to pay Kris. When Kris's scheduleconflicts, she contacts Leza, to whom Kris &quot;assigns all rightsunder the contract.&quot; Kris isc. liable to Joy if Lezadoes not perfo
UC Davis - ARE - 18
Jen is a third party beneficiary under a contract betweenKyla and Leo. Kyla and Leo can modify or rescind theircontract without Jen's consentd. only before Jen's rightshave vested.a. at any time.b. at no time.c. only after Jen's rights have vested.
UC Davis - ARE - 18
Clarice pays Damien $10,000 to design an ad campaign for her b. $10,000.Sweetwater Coffee Stand chain. The next day, Damien tellsClarice that he has accepted a job in New York and cannotdesign her campaign. She files a suit against Damien. Ascompensat
UC Davis - ARE - 18
Hybrid Corporation enters into a contract with Insure Service, c. provide Hybrid withInc. (ISI), to obtain health insurance for Hybrid employees. If funds for its loss of theISI breaches the contract and Hybrid is awardedbargain.compensatory damages,
UC Davis - ARE - 18
Rig Heli-Pads, Inc., enters into a contract to employ Scott as an b. reduce theon-site project manager for two years. If Rig breaches thedamages that Scottcontract, Scott has a duty tomight otherwisesuffer.a. do nothing.b. reduce the damages that S