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习题练习：Physics Unit12: Sound
本习题练习试卷来源于51fly国际课程 (https://51fly.win)， 为试卷打印版，您也可以在网站平台(https://mail.51fly.win/)直接 访问本试卷的在线电子版并查看正确答案与解析，搜藏保存任意题目到收藏集。 访问方法: 平台首页左上角"通过试卷号快速访问"输入试卷号 70，并点击直达试卷；或浏览器地址栏内直接输入本试卷链接 https://mail.51fly.win/test70.html  教师使用本平台可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力。
 作者: physics  发布日期: 2022-09-26 09:56    总分: 87分  得分: _____________

答题人: 游客未登录  开始时间: 22年08月07日 09:59  切换到: 整卷模式

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following is ib,5dkxc*9 s -)wkwpnv),t 7fxy;sfw a false statement?

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In general, sound is conducted fastest throuon. dw6njx4k ydp8 giy9x)/2tgh

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the speed of sound 4/pmu-x deytz +nom)8y q77vxin a steel rod?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the temperature of the air increases, what happens to the velocity of sound?ect 2 dm0hnixtv;)) -j.uchp. (Assume that all o-epuc;m0 htvjh tnx.2 )i) c.dther factors remain constant.)

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Compared to the velocity of a 400 Hz sound, the velocity of a y hh-r ,b4jn7m200 Hz sound throughrh bh-ym 4,7nj air is

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6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Compared to the wavelength of a 400 Hz sound, the wavdwa.t ),2kcd gelength of a 200 Hz sound in ad g2k)t. cdwa,ir is

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sound vibrations with frequencies greater than 20,000 Hz are ca iuid0jzy7rb;i h2k( 1lled

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sound vibrations with frequ,*;mdwy ;/4 nqssg;aq8uwwkh ency less than 20 Hz are called

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that a sound source is emitting waves uniforml t0vr1df 0ew:xy in all directions. If you move to a poi10w rvdf:e 0txnt twice as far away from the source, the frequency of the sound will be

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  For spherically diverging waves, intensity is prop-ublh m7t9( rss3p8hiortional to

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity of a point source at a distance d fm/ wy;)bjkhj(p89w j fsdwg;. 0)wmnhrom the source is I. What is the intensity at a distance 2d from the souj(h)nph bwmwgkj fjyw .w/)s8m0 9d;;rce?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You double your distance fromz.(-whhz * trv a sound source that is radiating equally in all directions. Whatwrth.h (z vz-* happens to the intensity of the sound? It reduces to

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You double your distance from a sound source that is radil-q3t98wp sz*cmdb5p ating equally in all directions.d 8pbtl9sc 3qwp5*mz - What happens to the intensity level of the sound? It drops by

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following increasesy+jfpys e4ae jwm f3.*5:x ft* as a sound becomes louder?

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You move slowly toward a speaker emitting a pure tone. What characteruom do2(d k5(histic of the sdhmo(k5 (2 douound increases?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What determines "loudnes:fszg,wf vu qm12oq+o ;/eq7 lyj9j 0hs" of a musical note?

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17#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What determines the "pitch" oa i+ j/ pk he);ve-err56:a -egivgzt,f a musical note?

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18#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  When sound passes from air into wlqu9- 93tr qlaater

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displacement wave2v0w j5*qnzwtk+f ,jdrh * c1j6k kp0qs are

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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider the standing wave on a guitar string and the sound wave generatdvzm:6vh,*gx dzj t5w5y u c91ed by the guitar asc516zhm95 vd z,tyvd*g :j uwx a result of this vibration. What do these two waves have in common?

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a resonating pipe which is open at s9e; k:fc u1km xwk(;rboth ends, there

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an open pipe of length L. What are the wav+/a+v-+dyd yeox ge84a 2wzou-d yjy3elengths of the three lowest tones e3 +wudjoxya4e+zg2yodyv a--y + /d8produced by this pipe?

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The lowest tone to resonate in an open pipe of length L is 200m5ccv:94nb d5;:d(oohw zoi p Hz. Which one of the following frequd oinc:c ;m:o w4dvh p59o(5zbencies will not resonate in the same pipe?

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An open pipe of length L is rci n+diwdt *xq3)n)n ,esonating at its fundamental frequency. Which statemen, q)id)nw n *xc+nd3tit is correct?

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25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a resonating pipe which is open at one end and ca zqhn-o 3r(8jvz:rede +o3w;losed at the other, there

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26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider a closed pipe of length L. What areh6 w -x;qg,kdt the wavelengths of the three lowest tones produced by this pw-,t; qkd g6xhipe?

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27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The lowest tone to resonate in a closed pipe of length L is 200 Hz. Whicvz6 oc5+ ;mnkph of the following frequencies wimvz;k6 poc+ 5nll not resonate in that pipe?

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pipe of length L closed at one end is resonatingl4 *5 ubokrxv) at its fundamental frequency. Which ulokvb4)x*r5 statement is correct?

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29#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A person stands between two speakers driven by the same source. Each speaksy8c ) dl4e2qker produces a tone with a frequency of 200 Hz on a day whq4 skdy2) el8cen the speed of sound is 330 m/s. The person is
1.65 m from one speaker and 4.95 m from the other. What type of interference does the person sense?

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30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In order to produce beats, the l 0md8dk04oxo)p 9lpk two sound waves should have

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two pure tones are sounded together and a p itx/z+cy(o2) zcmc j+articular beat frequency is heard. What happens to the beat frequency if the frequency 2zztc( i/coc ++yx)jmof one of the tones is increased?

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Doppler shift explap7i( ij4o o: fyp0d.ahins

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound source approaches a sta26syow qlj4zgwj,*3 etionary observer. The frequency heard by the observers2,o* ww3jez j6gqly4 is

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound source departs from a stationaryi*:be spe(e2jvp5tf(3c j/ uy observer. The frequency heard by the observi y e(*jcpbf5es3vp(u / 2:jeter is

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a jet plane were to double its MACHh1 ia*q,s 589lpw ccjg/bty,b-speed, its half-angle will decrease by a f,98jsibwqhcyp *,1c5gba /ltactor of:

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The speed of an ultrasonic sound of frequency 45 kHz in air is 352 m/s. What 5ub oy8fyhk798jmpko 2h/e ,lis theeb, yp8 uh2f85o/ojy97hmlkk air temperature?

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the ratio of the speed of soun40 / fjlrr;wxa:cwp ;xd in air at $0 \; ^{\circ}C$ to the speed at $100 \; ^{\circ}C$?

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本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  On a day when the speed of sound in air is 340 m/s, a batcc l9.c :tctn3 emits a shriek whose echo reaches it 0.0250 s laccc:9ct.3l nt ter. How far away was the object that reflected back the sound?

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You shout at a cliff, andbaa7cq cf+(/ o+ot(d j hear the echo in 4.00 s. The temperature is $0 \; ^{\circ}C$. How far away is the cliff?

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40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If you hear thunder 5.0 s af+w-vlg 236o6 vtimzehm+an kx6;b.gm( sf- mater seeing a flash of lightning, the distance to the liv;t6-g+.6xg o (i6lbnw23amk- mvh smfmz+eaghtning strike is about

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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An echo is heard 2.0 s from a cliff on a day the temper.r(fp2,fp 2 lb z,fcrnature is $15 \; ^{\circ}C$. Approximately how far is the cliff from the observer?

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  On a $30 \; ^{\circ}C$ day, there is an explosion. The sound is heard 3.4 s after seeing the flash. How far away was the explosion?

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You drop a stone into a deilzv7) a4e pvtue)c x-o(/u0eep well and hear the splash 2.5 s later. How deep is the well? (Ignore air resistance, and assume the velocity of sound is 340 m/s 4z7)tu0o/pe)- uvxi l(cveea.)

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The wavelength in air of a sound9s( eza.+ amlgbta- xeg9s ,9i wave of frequency 500 Hz is

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sound traveling in air at*-y5).q 4d 5ncdgil sd.eg z (ivaw4kd $23 \; ^{\circ}C$ enters a cold front where the air temperature is $2 \; ^{\circ}C$. If the sound frequency is 1500 Hz, determine the wavelength in the warmer air and in the colder air.

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46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the intensity leve *0wj*7k wvf 4v cuappby)d8i/l of a sound with intensity $10^{-3} \; W/m^{2}$?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the intensity of a 3g, ake,9gfx2 gr;hlb70-dB sound?

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the ratio of the ina0bj v1mfxl.1 uyx4a5tensities of two sounds with intensity levels of 70 dB and 40 dB 5auam.x bv41ylj01f x?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity level by 15 engines in as 9 qwqt(;8igr,e+xqb garage is 100 dB. What is the intensity level generated by one engtrbg+qxqs e ( wi9q;8,ine?

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50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity at a distance of 6.0 m from a s/uc q:r)kk 4izource that is radiating equally in all directions i )c4r:uqkzik /s
$6.0 \times 10^{-10} \; W/m^{2}$. What is the power emitted by the source?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity at a distance of o69ot/x;ysgdn58n gngl:th;zq6wl- 6.0 m from a source that is radiating equally in all directions is8 -9tn6ty; 5gn6wl:ogxsh dngl /;o zq
$6.0 \times 10^{-10} \; W/m^{2}$. What is the intensity level in dB?

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A barking dog delivers about 1 mW of power, which is assumed w) u5dmqz1nq, 41 hbvyto be uniformly distributed in all directions., zwvunbd)m y4h15qq1 What is the intensity level at a distance 5.00 m from the dog?

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity level is 65 dB at a distance 5.00 m from a barkin btis gq,0xh;ku03tw :g dog. What would be the int 03sutq wb0, ik:;hgxtensity level if two identical dogs very close to each other are barking?

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54#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At a distance of 15 m from a sound source the intensity level is 60nz 9/q ,;nwyxsx ywx16 dB. What is the intensity level (in dB) at a point 2.0 zsxn w6 nx1,wq/y9y; xm from the source? Assume that the source radiates equally in all directions.

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The sound intensity level 5.0 m from a point source is 95 dBygu)25k rz.eyp8f;bnn;ka8 ei8 af/ o. At what distance willeu8.fo)z /i; ;b8n knyekfyapa25g r 8 it be 75 dB?

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The third harmonic of a complex tone has a frequency of 1200 Hz. What ist lu* wk+ff:2six v24h the frequency of the fourth harmonic?w+*4kth if u2xvs: 2fl

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The frequency of the third harmonic of an open pipe is 900 Hz. What is the lenggiy )o ,ln0z6g wkssv hvcar-(mff9ab,g3,05 t yizkb6,f0,0s s9,aflgwggomvh rna -3)( cv5h of the pipe?

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The lowest tone to resonate in an open pipe of length L is 400 Hz. What is th n05y, ula a)wncni75he frequency of tha yiha5n0u nnl5),7cw e lowest tone that will resonate in an open pipe of length 2L?

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59#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An organ pipe open at both ends has a leng,sqrl6jv v98 a prlp89th of 0.80 m. If the velocity of sound in air is 340 m/s, what is the frequl 98v pjspa69rvr,l q8ency of the second harmonic?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 3.00-m long pipe is in a room wher- tbve+;xmdlu2 -tv1f*+ ka 8.7un. vyfbdzxx e the temperature is $20 \; ^{\circ}C$. What is the fundamental
frequency if the pipe is open at both ends?

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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The fundamental frequenca09wk+bpu9)l5ko o3b wiac j (y in a pipe closed at one end is 330 Hz. What is the freqj(i3o 9lwc 9k5+kba bpu)0waouency of the third harmonic?

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62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the length of the shortest pipe closed on one o8px( 1. 09ka jf1gsb6 fqfjxhend that will have a fundamental frequency of 60 Hz on a day whjhbso0xp9fk61a ( q8g j 1ffx.en the velocity of sound is 340 m/s?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 3.00-m long pipe is in a room where the temperature -c lvgch4w1m, b0c a 9uap17ebis $20 \; ^{\circ}C$. What is the fundamental frequency if the pipe is closed at one end?

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 3.00-m long pipe is in a roochvfl*2 ;6qmsvd :y;ho ln4 ;oa+rf.z m where the temperature is $20 \; ^{\circ}C$. What is the frequency of the second harmonic if the pipe is closed at one end?

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65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A closed organ pipe of length 0.75 m is played when the speed of sni;xoc t88zw )ound in air is 340 m; nic8)t xwo8z/s. What is the fundamental frequency?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider two pipes of the same length: one is open and the other is closg.tnyma ; h.dw 91yh-+ evb;tied on one end. If theigv mtw .;ten; yy hba.9h1+d- fundamental frequency of the open pipe is 300 Hz, what is the fundamental frequency of the closed pipe?

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two adjacent sources each er2,+utgt;nf .yh)ozzfv 01romit a frequency of 800 Hz in air where the velocity of sound is 340 m/s. How much farther back would source 1 have to be movedtz ,hfrugzy1.oot 0n )2f;+rv so an observer in front of the sources would hear no sound?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two speakers are placed side by side and driven by the same frequen 1g1)z/x+kz,cn2cqeb 4edkxfcy of 500 Hz. If the distance from azzkc gf2 e1b)c4qk+,/ x nx1ed person to one speaker is 5.00 m and the person detects little or no sound, which of the following is a possible the distance from the person to the other speaker? (The sound speed is 340 m/s.)

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two tunes have frequencies of 440 Hz and 444 Hz. u-o g bv)h3p8fng)wq6What is the beat frequency?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A music tuner uses a 550-Hz tuning fork to tune the frequency of a musi:jn77j 3homhn cal instrument. If the tuner hears a beat frequency of 2 Hz, m77 j3nhn:hoj what is the frequency of the instrument?

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71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The wavelengths of the sounds produced4/+uh, q t tj tix7z*j)yh)ido by two horns are 6 m and 7 m respectively. What betj)h dtqtyiz*4/+ oj,hi7xu)at frequency is heard when the horns are sounded on a day when the velocity of sound is 340 m/s?

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72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The corresponding vi g6f(eot idjg9v2q 1g 9kmue61olin strings on two violins in an orchestra are found to produce a beat frequency of 2 Hz when a frequency of 660 Hz is played. What percentage change in the tension of one of the strings would bring them to th1oe g2fu t9v9dqjg61gm6 (ie ke same frequency?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An observer approaches a stationary a9dn8dq kp;p05e abv7 1000-Hz sound source at twice the speed of skabd7a0v; p9pen 85qdound. The observer hears a frequency of

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74#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound source (normal frequency of 1000 Hz) approacheouqc3tb9l q48 -uz* bcs a stationary observer at one-half the speed of sound. The observer lcocq 3*b-quzb 98tu4hears a frequency of

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound has a frequency of 1000 Hz. If a listener moves with a d.gn3w irk8g /speed of 30 m/s away from the source, what is the frequency heard by the observer? (.gw/i8dkr 3g nThe sound speed is 340 m/s.)

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A police car has an 800-Hz siren. It is . .wbk mi s+)sqy kkk-y9kr./gtraveling at 35 m/s on a day when the speed of sound through air is 340 m/s. The car approaches and passes an observer who is standing along the roadside. What change of frequency does thew9y gbkkri +-q)./sm skkyk.. observer hear?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the frequency heard byw*eew v(j9r m5 a stationary observer when a train approaches wit5rwv *9 (wmeejh a speed of 30 m/s. The frequency of the train horn is 600 Hz and the speed of sound is 340 m/s.

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A train is traveling toward you at ha + 6dftfps:(120 km/h. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency d fd :hf6+as(tpo you hear?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are moving at 120 km/h toward a stationary train. The train .3nri9w8 vfb4 sg4a rgblows its 400-Hz whistle. Take tvgbwfig. 8sr 3n4r 4a9he speed of sound to be 340 m/s. What frequency do you hear?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A train is traveling away from you at 120 km/h. The train blows iqez1 6htwz2s3o)i p;h w -xegs*- qsd;ts 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency do yozq-;d16hsoi;ztw-g)h 3q 2sx e*w s peu hear?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A train is traveling awa82 4c )e6r7gmeqr lluiy from you at 120 km/h. It blows its whistle, and you hear a tone of 400 Hz. Take the speed of sound to be 340 m/s. What is the actual frequency of the whistem 4r 2lgl8i6ru7qce) le?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The frequency of a train horn is 500 Hz. Assume the)l(jnkop wse6 1lh e8- speed of sound in air is 340 m/s. What is the frequency heard by an observer if the observer is moving away from tese)n8lp kh61 o(wl -jhe train with a speed of 30.0 m/s?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The frequency of a train gay qbj3 /:ao1horn is 500 Hz. Assume the speed of sound in air is 340 m/sa3/oa gy qjb:1. What is the frequency heard by an observer if the observer is approaching the train with a speed of 30.0 m/s?

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84#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sonar is used to determine the speed of an ob xhs.4 )9qu6zagrm;h xject. A 40-kHz signal is sent out, and a 42-kHz signal is retuz hxx)u6qrm4 g;s.9 harned. Assume the speed of sound is 345 m/s. How fast is the object moving?

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The half angle of the conical shock wave produced by a supersogj6 cnbrq4)+y nic aircraft is $60^{\circ}$. What is the Mach number of the aircraft?

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A jet flies at a speed of Mach 1.4. Wy w7yq n1-xnzz*, qg77deq0yx hat is the half-angle of the conical shock wave formed-e7wq 71dz ,7x0*yyqnxnzyq g ?

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Concord airplane flies from the United States to Europe withw.s3h* tohun 9 a Mach number of 1.05 where the air temperature noht*9 hw3 .suis $5.0 \; ^{\circ}C$. What is the speed of the plane?

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