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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://autodiscover.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://autodiscover.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 a false sp-pd4mifqv52w p13y m tatement?

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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 condu3cwwh mkl+b)w5,as ejy tl1:4cted fastest through

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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 in a steel rod?a/v.a d hyimvg),dm* -

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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 velog x jtr+bs*4,z.e.s15eh jtjecity of sound? (Assume that all other factors remain s4jthe jb*ze1e+ , .r5tx j.sgconstant.)

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Compared to the veloz0 o00+p jzkctcity of a 400 Hz sound, the velocity of a 200 Hz sound through air i p+cotjk00zz0 s

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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 wavelmbq0 9h nnmw uevr5624ength of a 200 Hz sound in air ismwnm 6re 592q nhu4b0v

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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 calll v*a4;nw,hm ced

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sound vibrations with frequency less than 20 Hz ar(e2b q s7sp4wle 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 uniformly in all direc- 6wa)g8p 2o;,uxfjmrqa c3of tions. If you move to a point twice as far away from the source, the fre-6qpa3a;oo2fcgj)u f mxr,w8quency 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 proportional9c k.d jxh(ss,m57yeypb u- sjvr:)/ o 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 from the source is I.w 8vz56( zlrj(yokg :;m olf/y What is the intensity at a distance v(j;6r l(y/ogy8wfoz z :l5km2d from the source?

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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 from a sound source that i n+y;5cydne b+s radiating equally in all direb5+;en+cnd y yctions. What 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 distnve 6i.vwjj zpi;((yab)qa :*ance from a sound source that is radiating equally in all dire(p) e*i v( a;nj bvawy6:zqji.ctions. 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 increases as ,luk rr77hn-m)b/c sla 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 r3 89qc q8cgbopure tone. What characteristic of the sound increasc c83b 9rqgoq8es?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What determines "loudness" of a mu+ bc+weyuk 6,7n-beq usical 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" of i5x8a . w/f8qnjhmn.wa 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 fromg7.ip, ) zp+bqhhvq*usen0 u5 air into water

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displacement waves w-2fgxo5h0 t g(l:vccare

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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 gui h,c3oc,mvs-oqt zm7*tar string and the sound wave generated by the guitar as a result of this vibration. What do these two waves o* qo7 hc3ms tvczm,,-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 whiq7su.a5y (z7y0wkll qch is open at both 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 lefwpt9;j-c:lbk q2 +yangth L. What are the wavelengths of the three lowest tones produced by thisktpcql- :y9ba; +wj 2f 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 let iwjp48,a*+pr. icrnngth L is 200 Hz. Which one of the following freqpjiri t ac.4r,n*w8+puencies 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*0yej5dlfd(d0kjl;5wf1v(f9 cf c ai + p rtx: resonating at its fundamental frequency. Which statay(wf9j0 fr ;dd fft+1v 05*:x(lkpe5jdilc cement 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:p,uc2cm t (mk and closed 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 are the wavelengths of the threem+l rwn 4ny)l,k i5emv6kn. 9z lowest tones produced by thm i6zl9yl+ )mrvwnk 45kn ,.enis pipe?

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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 resono:hec p3(lf1 late in a closed pipe of length L is 200 Hz. Which of the following frequencies will not resonate in cleohfl 3p(:1 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 resonating at its fundaml sdbdp9r9s ( 8mrao-t-(h(djental frequency. Which statement i8o a-t9-jp mb sr drhdd9l(((ss 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 spq79siap;8dt wk6 b6opeakers driven by the same source. Each speaker produces a tone with a frequency op bts6iapw97dqo68k; f 200 Hz on a day when 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 beatytfed h9 b4xaxb13 7j0h f5uq .wb7s3gs, the 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 soun8g ;ij fa+ccl)ded together and a particular beat frequency is heard. What happens to the beat frequency if the frequency of one of the tof8j)clc i;g+ anes 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 expg .tp xb7rbsw*) -w*nzlains

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound source approachep v4c37,3+gsbh pdpak s a stationary observer. The frequency heard by the observer 3+ 3p7kchgdvpb,a 4 psis

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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 h 3ie meh9 f*)(xllcicorc95by9 :sd2from a stationary observer. The frequency heard by the observblm9e3 r992 :5f(ccdi o)iyc h*e xlhser 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 2ywq/zdcn.q b: u ekvnz6-5di 3/c*xmMACH-speed, its half-angle will decrease by a f3.5q*: /icwq/zvnu2 nxddm-ekz6bcy actor 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 is mkn5 -k6rgv92audd)rih-* qm the air temperatm-hr6uk *2 k)vg5n9-dmqradiure?

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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 thenyukqh,;wgov b ); .j( speed of sound in air at $0 \; ^{\circ}C$ to the speed at $100 \; ^{\circ}C$?

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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 in8(mb zhzupdf.j f: 4g, air is 340 m/s, a bat emits a shriek whose echo reaches it 0.0250 s later. How far away was the object thatjh(f fz84 g bz,ud.:pm 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, and hea5gp fhuu:3/bl+ y j2idr 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 after seeing a flash of c6qs-pey)c)e h)jh hl 06inj- lightning, the distance to the lightning strike is abo )cqh)p-hyj 66nh jl-i)e0cesut

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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 te* y4 c6. *2z1 lfxjvcjykde2bomperature 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 deep well and zgg5gpw/ j5/vhear the splash 2.5 s later. How deep is the well? (Ignore air resistan zjg 5gwvg/p5/ce, and assume the velocity of sound is 340 m/s.)

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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 sound wave of frequency 500.)jwqb,hsvele, 1l5 t 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 /zrrnf eem2m*y5,uy.1 4 kxqz$23 \; ^{\circ}C$ 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 level ofk kgs 3a-q.6i.ka*c fp 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 7.3sozwel rymjrz-2i0 3y;7a c0-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 intensithncab7;z s0n4n a 8h3wies of two sounds with intensity levels of 70 dnh8s 07 4zw;c3nbhaan B and 40 dB?

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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 a garage is 100 dgageah,zpw+6sw+d3 c p9r1y6 B. What is the intensity level ge, d+s 69erzha1y6cwwpp3gg +anerated by one engine?

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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 source that is radiatlsbp3ojfp 2g( 1iurc /5*zpw:ing equally in alci1 pjwp5z*(lsfo pr3g/bu :2l directions is
$6.0 \times 10^{-10} \; W/m^{2}$. 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 6.0 m from a source that is radiatingyk;f*glq8bon49olg 9 (h l ezrl2co-( equally in all direcy (r cgoql- 9lof8znllk g *2hb9e4;o(tions is
$6.0 \times 10^{-10} \; W/m^{2}$. 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, whichk2b2u6x0wxtq )tygm6 lrt07 a is assumed to be uniformly distributed in all directions. What is the intensity level at a distance 5.00 m from the d rlxy 22btu)wqgam060 t t6xk7og?

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The intensity level c4qnvk (.w ,cnis 65 dB at a distance 5.00 m from a barking dog. What would be the intensity level if two identical dogs very close to each other are barkin, nvqwn c4k.c(g?

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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 intensi )i,zgm2 ny9q.1w xtzq,px+ae ty level is 60 dB. What is the intensity level (in dB) a2 ,q xyze.t gi+m1q9xaw pnz,)t a point 2.0 m 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 da/j9l vu .x:39kuxxl m from a point source is 95 dB. At what distance will itk du9lux.9av/ lxj3:x 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 iskcsgx4law58ba h pcra27 .u0a+s56ul 0y,ma g the frequency of the fourth harm u,bcla gmga5 l00a.hp 5ay4 k7s 826racus+xwonic?

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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 i3d q(-v(mgbn vxv. xe:s the lengbvx vg ndq:e(.-m (v3xth 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 o:g1fzzejh 9t +-q.zqj f length L is 400 Hz. What is the frequency of the lowest tone that will resonate in an open pifzgqq-ztj +ezj :9.h1pe 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 length of 0.80 m. If the velo: wzi c5lw;7ppcity of sound in ail:pzw57pci ; wr is 340 m/s, what is the frequency 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 aho:l8)k j0j3ang)dcl s.w7 dq room where 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 frequency in a pipe closed at one end is 330 Hz. W /cnrmrfr)a6- og9( iahat is the frequency of the third harmonicg() oniaf 9rar/-cm 6r?

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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 op0xkdj -ys0syra-24 k l72 yrpipe closed on one end that will have a fundamentaro7kla 2ypyd04sj x0--sr ky2l frequency of 60 Hz on a day when 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 wherf asjya np2gym etut.ol80k.)u p -7.9e the temperature is $20 \; ^{\circ}C$. 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 room wherez8ih 1xt,l1fr 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 t4h)mv37 km9 rqg+ou wnhe speed of sound in air is 340 h3g 7qvw4um9+k) onmrm/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 6*j8- bgdl znjis closed on one end. If the fundamental frequency of the open pipe is 300 Hz, what is the fundamental frequency of th-g nzjjd6 *l8be 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 emiqjbg5 x7 e7oy2t 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 moved so an observer in fron5j oe77y2b gxqt 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 frequency of 500 Hz.bk: suaqxk2,c 4) q/sw If the distance from a 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 sq/4k2a )q xb:uk w,csperson 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 bi qc 2,4yjm-w440 Hz and 444 Hz. What 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 550sfdn9hb2ky5 bzpsh87x)cm q emy/7*: -Hz tuning fork to tune the frequency of a musical instrument. If the tuner hears nh2 s:xzc 9 e7fhqmy57 sm)y/b*pk b8da beat frequency of 2 Hz, 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 produced by two horns are 6 m and 7 m respeck,aqp psz z 1e:npp))r4k;;*/ddw6cez w.jf etively. Whpqj) :6pczk;zpw/a ;,dre*wk.4) seepfzn 1dat beat 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 violin strings on two violins in ak n3x1 - kptx6ze c1,dh71p;z2mc mzqwn orchestra are found to produce a beat frequency of 2 Hz when a frequency of 660 6x1q-7,z tpe wkxn 1 ; mdcc13kzp2mzhHz is played. What percentage change in the tension of one of the strings would bring them to the 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 stavdpa7l0 e 1pe5tionary 1000-Hz sound source at twice the speed of sound. T5l edap0v17p ehe 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) approaches a stationary obihwo97xo-g 70f v*d rcserver at one-half tfx gi0d*chvo -77orw9he speed of sound. The observer hears 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 s6kqt; :lakjs7, /wana speed of 30 m/s away from the source, what is the frequency , as6tk7al j: ;qwksn/heard by the observer? (The 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 travbtqa98t h:s;h3jx(w i eling at 35 m/s on a day when the speed oft;i a8jwbq:x9sth( h3 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 the 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 by a stationary observer when a train apprcnou7abkw3ktp* 6v fj:18oy)oaches with a speed of 30 m/s. The frequency of the train horv1 bo*wa nj3o : 6utkyp8)fc7kn 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 120 km/h. 1f u ikp8+)j1(zklyvdd2a,lzyd, ox- The train blows its 400-Hz whistle. Take the speed of sound to be dazf p2yv,k1k+uxl i z,)oyjd(ld 81-340 m/s. What frequency do 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 statinxo9u7d wp)ha9ec/:konary train. The train blows its 400-Hz whea9p/ kx o9hwc7: n)udistle. Take the 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 awzho-2u*ps /lolo 16 vjay from you at 120 km/h. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency do you h /oju*1plh2olz-vso6 ear?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A train is travelingkpfqte6j g( r3/*hzx+q3l8r s away 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. W8f33(sxl 6tp+e/jzqk* r qg rhhat is the actual frequency of the whistle?

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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 d( 4;csafr pa.2 8sadiHz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by an observer if the observer is moving away from the train with a speed ;r.dp2f a8s4a(adicsof 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 horn is 500 Hz. Assume the speed of sound ixey1w*j9lpp q1v* o0f qqxb(( n air is 340 m/s. What is the frequency heard by an obse*y(q 1 *fq1xpjqb0 pvl( 9oxewrver 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 m;1-:x zbl6tu i m3hn de*qzzxp6t)u+ speed of an object. A 40-kHz signal is sent out, and a 42-kHz signal is returned.xqhetxn6z -zt)3b:+1pi*u z;m m6ldu 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 conical9s s- jvmg8)(bsl -rdb shock wave produced by a supersonic 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. What is the hac u6(fvj/) duplf-angle of the conical shock wave for6fu dpv(j)uc /med?

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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 Unitedq1r-t;1a ojd; lz:9iin ni wz5 States to Europe with a Mach number of 1.lzwzi a9 :dq n5j1-i1irtno;; 05 where the air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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