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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 statep+ zc7 omjxv*w3rme,/ment?

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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 through zaqoz3 ,6rxr3- h/dq7wby rc+

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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 soundc+fr.ys two1u+ on4rtn h/e+7 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 increase d-rl9ru2y7zws, what happens to the velocity of sound? (Assume that all other factors remai-yrd luz7wr 29n 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, ther2q3bl;k8m f u(phlf * velocity of a 200 Hz sound through air lu(2 *fr;kbhfq mp83l 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 so iml m63lff+1 vez7g:qund, the wavelength of a 200 Hz sound ingf:6z3v+lmmel7 1q fi air 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,ltg:y(k0*d7s5cmft y l; sx0k000 Hz 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 than 20 Hz are4:gvbltvsn 96( jubt; 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 wg.4u7yi m;e 3pp jkk3dmix 4y,(.rwqaaves uniformly in all directions. If you move to a point twice as fr7diq(.iyk xu4g ,33je wakmpy;.p4 mar 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 ;r9jy ngt:ff6 ;rmnxgx/mz*8waves, 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 sourc5*c.t je9 ed13m3vtnznrple 7 e at a distance d from the source is I. What is the intensity at a distance 2d from reme9 *cen7z 3n 15 lt3v.jtdpthe 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 is rak2/rzt5y6if wlr;5d ediating equally in all directions. What happens to the intensity of the sound? Itwfzy5t26e; /lkidr r5 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 radiating equaljxt0.fl :v 5zoly in all dir0x: ftv5.j zolections. 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 a sound bexc-c 4ksz0evoo38 , amcomes 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 emittingr.7t d8 v4ayd z,j1muuc2kas1 a pure tone. What characteristic of the sound increases?rt d7 uk.2z d,8j4ya1avcsum1

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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:iil,s ib i3gr 0g7zss64wp22sapu /nl e )4gm 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" of a r 4smu98x q(0 x0bw :he)lrtzymusical 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 apqu-cmt,r/2 / r5 trawater

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displacemenmqpx*r 52s :fq(5bfwa t waves 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 sounciils o3 ocy,u29tmv3p 5yi .3d wave generated by the guitar as a result of this vibration. What do these two m.i5c3ooi,p 9 vul3yist y c23waves 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 pipeovc fm17 c-adtu/p cmja de z75p)k8+8 which 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 length1uaut(l 1m2y do d9:tf L. What are the wavelengths of the three lowest tona121d dy(uftot :9um les produced 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 200 Hz. Whichcml uvd) 7:yj2 one of the folllyu :m)c2v7djowing frequencies 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 r0xx0vp.99xw q) ewbvuesonating at its fundamental frequency. Which statement is co.vu q0wexvb)xpw9x09 rrect?

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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 ecd lm;j2)vw)p nd 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 sek yrz98g 4ije0tx3b8-ev mdty. +f:L. What are the wavelengths of the three lowest t .+v3-b8t y08yretegedkmj4z: fi xs9 ones 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 200 Hz. *b 1zef a bc: dj4jhut*1;zym( Which of the following frequencies will not resonate t*h ubdc1zaej1:jzfbmy;4 ( *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 resonating at its fundamental frequ*i4g(7( tdgfy(iofa lk/gyj *ency. Which statement is corjt4 dio ga*/( yglgy(*f7if k(rect?

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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 samevizjovy7a9f / sb e,/zci0ni0ct14a5 source. Each speaker produces a tone with a frequency of 200 Hz on a day wheni0c1, v5nfycj0tzi7/ v e sboza 94a/i 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 sou; zbsl;y+tn- xnd 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 particular beat frequency is heard. ds7co8w1x8kn 4g. h a)snurs12 t 7skiWhat happens to the beat frequencik ws827hcds kons4a.8 tru)1 7xngs1y if the 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 explaqe-xdxp8 gzj/ri4t6j 6yb 1)jins

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A sound source appro jao5bt y,w j(bse)r-.aches a stationary observer. The frequency heard by the observeys5.o)a e(-r,tjbb jw r 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 stationary observer. The frequency heard by k /j)hxajqy++1f+.u0 s27zfk m pzcpzthe ob0zh z fxmk+)q 1ua p/c7zp2sk.yf +jj+server 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-speed, its half-angle will decrenpp doc)8ft*/ w5c 4mease by a factor o4/p wc* mftd8) oncpe5f:

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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 wj.bu9kcf 7 d+zvb/yhl;. s4eof frequency 45 kHz in air is 352 m/s. What is th le/d.+b7bj;hkwus 9v.4z yf ce 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 sound in:j*q ,keub)ka 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/s, a bat emits a shriek w2y3 ;lyiar*r ahose echo reaches it 0.0250 s later. How far away was the ra3a*l r2i yy;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 th u85pe30x )qvntl.qh gs)b2oee 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 aft)o0,f pvd/ygd-(jbe h er seeing a flash of lightning, the distance to the lightning strike is f)dpoj (/g -ed by,h0vabout

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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 lxg1vj1x.e/ a9revv-x4z3x xcliff 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 theh beq.84p crh1o4al(qw5 mos6 splash 2.5 s later. How deep is the well? (Ignore air resistance, and assume the velocity of sound (m8ohbqapc1.olqe 45r w6h s 4is 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 frequencfw; 5r0-lhin oz0sp;gy 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 a(b9;by. 4gfzdqlqy6 it $23 \; ^{\circ}C$ 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 sound with intensimu/smsy*4*fi- dfq * lty $10^{-3} \; W/m^{2}$?

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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 nw6vuc* j4f xu qlsyb*-i:7 -rof a 70-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 int7rtg+ b.unzn5 ensities of two sounds with intensity levels of 70 dB 7bnnug+5trz .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 dBuh0 d;;6ok-r pzcis3w. What is the intensity level gdkh3wsu ; o6 c0z-;irpenerated 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 radiating equally inch;f))+cfdcm lsl7)y-eo v4c a4f)-;vylc)+c ole dh mcfc)s7ll 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 xr*cdf* zgwk9 8.jjf4is radiating equally in af 4*d.*zrjc9jx8fg wkll directions 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, which is assux7jw)p+d n+x +yzu9hbg- yz8 wmed to be uniformly distributed in w )jdgpyb9n+zhx 8-x+zy+wu 7 all directions. 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 barking dog.5eusc0.w v7nbeg, a r. What would be the intensiuvce7n. a ,rwb5esg0 .ty 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 c0:r n,ddd w;viqt-1v 60 dB. What is the intensityrvvcdq0w,d dn- :ti1 ; level (in dB) at 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 m from a point source is 95 dB. 2ifvoi76hs *od fud8+cli -y0At what distance wils6f7i2* luoidvi 8 hf+ cyod0-l 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 py7scs mgim17s u2b1.a complex tone has a frequency of 1200 Hz. What is the frequencs pm7sum s2yi7g11b.cy of the fourth harmonic?

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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 ha/ v6ir( 4l +vr lkvmqyej1;t9lk;e6p jrmonic of an open pipe is 900 Hz. What is the length of the mel+ 1lerk9 ;krjl yqtij /6(vvp; 46vpipe?

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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 the fr :u z(t0mn*eov++vnfrequency of the lowest tone :*v 0+r znomfuv+n(etthat 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 length of 0.80 m. If the velocity vt w l 2ju ,zrn9,z,upru0,o,zof sound in air is 340 m/s,2 , lu0r, nozp ,9ztuvwz,jr,u 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 i qism8qgmk2f1y /8eynqfx+ w2 ph)y5e 18mn.rs in a 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 5 efp2sui.f ay0rwbkb-*aub6 /c ) 7ukone end is 330 Hz. What is the frequency of the third hak abs*f6b u/wfkcu5ae0-iur2.7b p y)rmonic?

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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 jfki+yc e 0,;fone end that will have a fundamental fre y+f i0,ec;kjfquency 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 where the temmjs8.+c0; w6lw4fa sb5fs. phijfx3 zperature 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 tempergrwr 0zs :o 0ai;o-n0rature 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 sound in air 0yq5rjv1 bxtrj n .-r6is 340 m/s. What is the fundamtxyvr-rb5 61rnjj 0 q.ental 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 i3t t(wgx-3 tvv ioprm7as/2q,s closed on one end. If the fundamental frequency of the open pipe is 300 Hz, what is the fundamental frequency of the clv ,2po/mv-gt (ta 3wrt i7sqx3osed 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 freq z nk:)6q+uu8w 2vk/e7pmotk kuency of 800 Hz in air where the velocity of sound is 340 m/s. Hou7q p +keuzwk2)m8on kt: 6v/kw much farther back would source 1 have to be moved 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 placebt,gtdob27 u oi))q. (ti7xpwd side by side and driven 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 2 odi(g7tiw) pbbxo.7u )t,q tspeed 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 frequezf+zg (-cyf 5gncies of 440 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 550-Hz tuning fork to tune the 4mev.k f xi3i8frequency of a musical instrument. If ti48 if.e kmvx3he tuner hears a 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 hop 0k ;mn5w.4zs1k9 vgywxs ;jxrns are 6 m and 7 m respectively. What beat frequencksx ;yk 5mg;wj1 pwz xn.09vs4y 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 violiajsm uhh//:/9h hwe(pn 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 theem:w/ /hh p jas(9h/uh 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 stationary 1000-Hz s6iittf 3r,f2 5 v7rcqdound source at twice the speed of srt6i2 7,iftc f3dqr 5vound. 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) approaches a stationary observem tmfom5wuu9)v,4 0 hjr at one-half 5,)4tum0o 9w mmjvhfu the 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 a speed5/z s*otp308qvxxq vl of 30 m/s away from the source, what is the frequency heard by xsl qzx p*03vtvq/8o5 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 traveling at 35 m/s on a day when the ;k5ros 4gjo*g c:soq 1s4sx g2speed of sound through air is 340 m/so*o:;kjq g1s 2cggxs4s5rs o4. 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 by9fbt)qqr4y.f ( fej+o4+jxew a stationary observer when a train approaches with a speed of 30 m/s. The frequency of the tratf+4j) y(e xfw.qorb+j4fq9 ein 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 120 km/h. The train)ef*c9vyp2tf8 eqy1 u blows its 400-Hz whistle. Take py9e2q ev1 uy)*8ftcf the speed of sound to be 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 towf xf 20i8jly/mard a stationary train. The train blows its 400-Hz whistle. Take the sp y ij0f8m/2flxeed 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 t*,qq.ic def( wrain blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. Whatdw f(i,e.q*c q 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 120 km/h. It blows its whistle, and you h+1o74t41z /fq srwa6. vimzezhwp8th ear a tone of 400 Hz. Take the speed of souns az +4zmt1oe7w 16w4 pz.tifv8 /hrqhd to be 340 m/s. What 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 Hz. Assume th ypn:e adwy(b t/n7h//e speed of sound in air is 340 m/s. Whyn/nt:wh( yp7ebda //at is the frequency 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 sounbh370) i(1yncic.wrsz pvberc/ijm gh9937fd in air is 340 m/s. What is the frequency heard by an observer if the observer is appro3e7vyi)9bhsi rw j /9b07mc31 (nzph.f gc ircaching 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 dete hmu53uy: ,/p1jfo1p4okthcho q.f9 rrmine the speed of an object. A 40-kHz signal is sent out, and a 42-kHz signacqhy u .k/rf:jp,h1 umot 5p9o4o1fh3l 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 aircra++. +creael ,/tj:kv/ 5wb0mzl r7f .zil gshsft 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; *k78wx o,4clvs*(tg k1iz6pzpuj k4dpfe- t of the conical shock wave fo4,4dp*otj7 k uvxe w k;z6lp 8p sfki1t*g-zc(rmed?

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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 ate4uqh8 t3t/ a. bi*jStates to Europe with a Mach number of 1.05 wherbt*qi . a8t3/tahe j4ue the air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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