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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://autoconfig.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://autoconfig.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 statemen :na1 je7 za a1vktp bay773t1 z8aqx4l6arw6at?

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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 uky5 (87lyjmhthrough

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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 .buhipn53a/w6 4rc ,t9c kfby0tsyq v.hd +z8sound in 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,t;7 o/(n,d q;od3byl pykkkx the velocity of sound? (Assume tpd d kkko;;t7n(,q3 l,xbyoy/hat all other 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, mn m s0i4;/zdathe velocity of a 200 Hz sound through ai;4ansmi /z0 dmr 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 wavelenkq tny+.2,dh 2vb2zn wgth of a 400 Hz sound, the wavelength of a 200 Hz sound in z b2n,kt2v dywn2 .q+hair 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 H +a ,egb+jddv)xavs--usp7t(ajj( s4z are called

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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 th1up, 9yhnt a9oan 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 uniformly in all directions. If yl:c2sqqm e(yk4o w .p*mw0cd a98*ijpou move to a point twice as far away from the source, the frequency of the souwkq*9mcjl 0wy8d. ep(2c4q:siom p*a nd 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 diverg,*vi.vd:w98 8v5x jxsayxy2wb u )al*2x cydhing waves, intensity is proportional 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 distanfql0 b+)x(b sbce d from the source is I. What is the intensity at a distance 2d from the sour+ qxf0b (bl)sbce?

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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 is radiating equally in all dibx dx(1 8j(xurr1(8 xxxdjbru(ections. 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 distance from a sound source that is radiatingdi,/iv, pva3owo-5s n99i vuj equally in all directions. What happeio, si5a/u vwvn,3i-9v9pj do ns 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 a sound becomes louder?71d/jc rftn9puc o)6k

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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 fl eat,f* :u4 7-qiyvua pure tone. What characteristic of the sountv*y4e,u : 7iu-laffq d increases?

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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 musical note9(py* r c12,oktun0v cqimu6 j?

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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 a musawc7bc fl( 9hwd75tl 2ical 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 wate mw e 9mz jl1a)(xgunsitrzm)8nt6 +49r

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displacement wtlh5m6r :wl/ w w;y;k qfir,y(+mcsz;aves 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 generated by tkyc dpk9dei4 ji, 4(- u(*zfcehe guitar as a result of this vibration. What do these*ju de ikdk-(4fce 4,iz ypc(9 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 w f*nrbux /sexe l(53kt+hhl;. hich 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 length L. Wh2yco /3hlgc+ hat are the wavelengths of the three lowest tones pr/gch 32lch+yo oduced 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 gdskdlv s*02(nitm (y/1ww2s an open pipe of length L is 200 Hz. Which one of the following frequencies will not1w0im n/st(kwvd (2dys2 *lgs resonate in the same pipe?

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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skysky1258，获取更多资料
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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 resonating at its fundamental frequenszxtdqmw*u )v(i 2s h6e i*-8vcy. Which statement is co2 i*- )vxvei*m6s( wdzuqhst8rrect?

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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 o+zjm7 u8f.wz uz c,e i./ld-ybt (yhp,pen at one end 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. Whagq2t q8)ro*kwpw n*n *t are the wavelengths of the three lowes n) nrwkpq* 2g*8t*oqwt tones produced by this 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 resonate in a closed pipe of length L is 20ce (lgu e48fo,0 Hz. Which of the following frequencies (gle,8o cfeu 4will 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 resonatin 2ij k sz-0ttrng;6s;kg at its fundamental frequency. Which statemen i kgs tr;js-6kn02zt;t 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 sperf 360p qob6fa-0uviwakers driven by the same source. Each speaker produces a tone wiw6fp0qv0ab -rou6f 3ith a frequency of 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 beats, the two sound waves soyy,dhku9( pm*:4xq rhould 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 particular beat3,y p,8dqvnxn l h;l;a frequency is heard. What happens to the beat frequency if the l q,,;dnxhpn3ayl; v8 frequency of 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 explainoc9n;7 p uxfroj 0o)w2s

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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 stationary observer. The frequency heard by n6z:vf dr7ts ;the observerz7nr6s: tf;vd 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 sp vcul9eh*vh8;j kt5 2tationary observer. The frequency heard by the observer hjlc v*k29vupt5;8he 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 MACH-speezprsv f10doz xh/:x. 0d, its half-angle will decrease by a factor hv0rx/z1o :p0.zxsfd 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 freque* qri r3wq2sf0ncy 45 kHz in air is 352 m/s. What is the aqir2 0r*swf3q ir 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 ofy.kduet t+ kp0k(3,uq the 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 in air is 340 m/sx+7 deux*ertf1o7 a1 r, a bat emits a shriek whose echo reaches it 0.0250 s l117 trrxe+e* ux7da ofater. 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, and hear the echo rcuu/ ,+. vvu *dprl 8ob3j0rlin 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 seeisplv xioev(drs q.9n1 9j .p,,yja y/*ng a flash of lightning, the distance to the lightniv(y9.syes dp iljo9 nvj,*p,1q./ xr ang 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 frp: ebot/1g uk3rapl..om a cliff on a day the temperature 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 hear the splasv2q iohg.7* 5 klqf8vih 2.5 s later. How deep is the well? (Ignore air resistance, and .8oiq* f ig2qhk7v 5lvassume 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 gy:2gi0:pksno:3iricj/ri* w7r (ga 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 aiu8u42nrpm n ga9qs40cr at $23 \; ^{\circ}C$ 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 of a s *5 br )b;rxn;/whoz; v7u 5pzxiggxq7ound 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 m:d fl6 ,o;dcnj.- ihbqjm*9y70-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 intensities of /hscopax (zwga;b3,: two sounds with intensity levels of 70 dB aaa c hwg3z /p,o(;bx:snd 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 ttjw +pu5c9l7o9 tm- o100 dB. What is the intensity level generated by9otpwu79c-+otmjt l5 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 frzm3q9,zrujt tvmd/+5 om a source that is radiating equally in all direct qtjt z9r+d/5zm3 vu,mions 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 radiating equally4bd3r)e jq1m;mg * boi3o m/tkoj eokl3y ,5i0 in all directions is,;omqd3ie*3 t/e)lmgoo b1 ji y0okmr 4 53kjb
$6.0 \times 10^{-10} \; W/m^{2}$. 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 to be ugyiz9flw 1.-uyx;s; iniformly distributed in all directions. What is the intensity level at au;-i9fz. lx syy1wg; i 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 distan7 yuu1-qj (*ofhyj2 kvce 5.00 m from a barking dog. What would be the intensity level if two identical dogs very close to each other uy1 h*jyu k(2- ovf7jqare 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 loq+mvb+0w u-x* t,xvlevel is 60 dB. What is the intensity level (in dB) at a point 2.0 m from the source? Assume that the source+w0xv-vo ml+*bqt ,ux 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 lekr )q bd/ -bg.h(xk4v bp+lg)dvel 5.0 m from a point source is 95 dB. At what distance will it be 75 d4r+ bgbbd()l/gq.pkdx- hv)kB?

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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 1200mt(wid u1l+b. bj7rn0 Hz. What is the frequency of the fourth har j( 1bnw0iu. bmd+7ltrmonic?

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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 +lhyig)t.,xao .)ew vlength of the pip hxyvow+)..gael i, t)e?

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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 thea lb:a 0s0vb86m 3ox--mumh v)ij.e sk ol 0x-0mv. mk6i3hb 8 v:)-a sbasmeujfrequency of the 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 wzf 8i/xj (r0fk1ee.qhas a length of 0.80 m. If the velocity of sound in air i/.8f erjxz(ei wkqf01s 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 a room where the temperaz+60zqia(g tg cx,xl8 ture 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 kq1u8y:wp0u a 330 Hz. What is the frequency uuqwp k8ay0 :1of 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 yneh32bj;ly.pvp 6cz9 v0ibi-0d0 ugone end that will have a fundamental frequency .9il6v0z0 dvnj3b2i b0-pcgy ype u;hof 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 ;+,h5k ozmhio(tvc6 ea room where 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 where the temperature i vnl/*zljgut0 sph,8,q vn*)b s $20 \; ^{\circ}C$. 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 souoqnu wdc-7+ 3wnd in air is 340 m/s. What is the fw w3o+nc -q7udundamental 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 closedp3o yip*l/v-pc wb:* /h -cwbf on one end. If the fundamental frequency of the open pipe i/b-*vfw-bcli ow /3 p:cyph*ps 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 emit a frequency of u9;422hyhbzqb*,yc,twnln ihu+ 7 xq800 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 front of the sou7h lh w*inq;xht ,n49, qbzb2uyc2+yurces 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 2/ r h /)plfw+ulr2k(yn0syrkw -j3ru by the same frequency of 500 Hz. 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 person to the other speaker? (The sound speed iskhjr(kw uf ly pr u/rlr02+ w/y2sn)-3 340 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. What is the beat fre sg o8te4q)-ui d:6/qn-r forrquency?

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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 *ehy5 hvpgu7: the frequency of a musical instrument. If the tuner hears a beat frequency of 2 * 5huvhgpe 7y: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 thpw4;1bb9doe)l+ q: )tmhkb eve sounds produced by two horns are 6 m and 7 m respectively. What beato) e)p1 4ke9whd+qm; bbbl:v t 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 hpwii4p / l;q1g 4o-vuan 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 thi qp;g4hviw1pu 4o/-lem 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 stationars:u,si2cm v)uik6c f .y 1000-Hz sound source at twice the speed of sound. The obser 2scf.,iu:k6m vsu)civer 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 st ilrq)y-1a)6wu4qb rs.0ue. qmgk r5a ationary observer at one-half the speed of sound. The observer hears a frequ5qi k0.qlm sr aur61).ag)r wq ue4yb-ency 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 (g bii/ k+)/uhmwsb2 nof 1000 Hz. If a listener moves with a speed of 30 m/s away from the source, what is the frequency hn i+) h2sk(/bw/g miubeard 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. 2x6bdkj+ pfe6p7zte3 It is traveling at 35 m/s on a day when the speed o276xd p ftek 3+pjbze6f 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 app*g8q(2i7tkqn f fzl3s roaches with a speed of 30 m/s. The frequency of the train horn is 600 Hz and the speed of s7sk3ifl2f zgtq(q*n 8 ound 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. The train blows its 400-Hpolv 8n;1tw oj/ x 4j6rs.yw/lz whistle. Take the speed of sound to be 340 m/s. What frequencyt.s4nxo 1 vl /wr6yopj;8w/lj 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 stationary train. The trai+dvwky;u u9 kwqh;zj, ) 6vnc3o2 -nihn blows its 400-Hz whistle. Take the speed9 + k hc2kuv)n ;hzqw dy3nu6oiwv;j-, 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 kmhss)5nu*m1wp2jz ri8 /h. The train blows its 400-Hz whistle. Take the speed of sound tpswhz jn mi*u)518 2rso be 340 m/s. What frequency do you 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 away from you at 120j(w (i fv:x-ajup( *qw 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 ac*(v(uj:jfwaqx( wpi- tual 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 Hz. Assume the speed of sound ib ll.dp b5p2ag2v)5oe)b:xpin air is 340 m/s. What is the frel vb2p:ed x)gbi2.bal5p)5p oquency heard by an observer if the observer is moving away from the 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 horn is 500 Hz. Assume the speed of sound in aizdr/bk)s--b jkiy3 4 er is 340 m/s. What is the frequency heard by an observer if the observer is approaching the train with i3 e-bbkz) -dyr4s/jka 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 object. A 40-kH3 yl8nkp s62phz signal is sent out, and a 42-kHz signa8h6 p2 nlsykp3l is returned. 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 supersonic aircrab.7 sxcxo3gq/yk2(1xxr hx-vl opu5 fjg)9.w ft 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 half-angle of the coz w 27xq-m.74kfzpwsb*ual9knical shock wave form 9kkam.zxw7sqf7*b- uw2l4 zped?

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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 with a Mach number1q lzfv85s+i0q 9lqfd6-c/i cgvh -ro0aet+ s of 1.05 wv-tqi v5es f0c1+dfs h lqg9/z-qa8+6cri0lohere the air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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