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习题练习：Physics Unit12: Sound
本习题练习来源于51fly国际课程 (https://51fly.win)，是在线习题练习的打印版，您也可以访问本平台网站(https://51fly.win/)直接在线完成(注册并登录账号后在首页左侧输入试卷号 70 即可在线作答)，，作答电子化后可随时回放，查看每题答案与详细解析，搜藏保存任意题目；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。本试卷的直接作答链接 https://51fly.win/test70.html
 作者: physics  发布日期: 2022-09-26 09:56    总分: 87分  得分: _____________

答题人: 匿名未登录  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 ismcqse9fl41 5 tzn5x3u 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 fo63ccro(-nf nyi,i (yastest 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 steemz)+j3/z e .ae3d ph (xbmn3bel 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, w.i*ae7 cq+jp dhat happens to the velocity of sound? (Assu iaeqpd*c+ j.7me that 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, the velocity of a 200 Hz sogdie 6 0axg* h:plrr6qtqb +8fq;s7 (fund through air isdbq0t7p6gxar; rqqhe+:fl6 s*fig ( 8

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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 wave tkte37w)5 ohxbkj(a(length of a 200 Hz sound in air itkx( )3awt5oj7(ek bhs

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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 thm13e vj :t wqcebo2(e:an 20,000 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 lesswtek802j;gm3s bjy wz+ nzs/ 2 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 som3feu ;evox4g l,;4ho i 3bov1opri/;r+ f; epurce is emitting waves uniformly in all directions. If you move to a point twice as far away ;mi3r3; efp+ubopvrf/vh,;4i1og e; 4xe oolfrom 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, intensityv ,zs wh7csomu3+j u6ln qi0uv7ad1+; 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 distaw,cw y.s/-;yhx5nj i/+ lyzdm4)bgxjnce d from the source is I. What is the intensity at a distance 2d from dy4 +by w;,h l5m.wxg - jxs)/jc/znyithe 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 radi54cpv/kzlm gp4 y9ebv61e)xyating equally in all directions. What happens to the intensity of the sound? Ix6 k ) gzecpp94mvy /vy51l4bet 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 equallak-ziei m5,ico7n +0 ty in all directions. What happens to the intensity leii, 0o+5-tznic ka7emvel 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 lou an:ikq q;w-n5der?

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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 e0mxa 7:jv4 5wdu- ozjamitting a pure tone. What characteristic of the soj7dwx04-z ujv am: 5oaund 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 8,2ilmpo3hlsiqpq-5 " 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" 4-l59 e :br ijdokcvs)of 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 t i f84cl(:g/ jywwds: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 a b -0hlzq6f/o*le 5gdkre

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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 thyg u2szy/w4 m+e guitar as a result of this g/2u s4zym+ ywvibration. 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 opeot a9py rg16ht; k28yl 9s*fjvowo +9sn 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. h5mftq,:z(lff djak/+dm0o q(: zcq) What are the wavelengths of the three lowest tlf0kfaq , /)q: jmh+ (d:q om5zc(dtzfones 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. Which oxhony0 yuo (jeor) :8w.fb :,mne of the following frequencies will not resonate in the same pipr(h0yo:) nj, of8 xyo w:eb.mue?

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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 isfp9l f- ylkl:7 resonating at its fundamental frequency. Which statement isyl: l7 -fp9kfl 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 onk, .apz8zjfp ts) +zy6w; v(xoe 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 (vua 2ux- 6k6fyj2zp rsyx3s 4of length L. What are the wavelengths of the three lowest xju-vssz2y6r( a 6f3kupy42 xtones 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 pi p7koi9 ki9bngkd *e.2pe of length L is 200 Hz. Which of thekkgn kbp2id*oi .99e 7 following frequencies will 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 resonating at its fundament; xeb 7j+ojli(al frequency. Whicbijjo7l+x;(e h 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 speagg.ez1j+xzif(- ou8(tzahsm+ 0 (k vtker produces axg( vt.(szue(h+i8k+t ogzm 0zja1f- tone with 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 should hao; 9q6uphfu.j5dj+ t dve

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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 hed4;(et6wz ;v ydds)ux 9brh*mm)p mz6ard. What haerb64d9*)mzy;tshd );md px m zv6u(wppens to the beat frequency 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 expj:nia3mlx)kt x0 s)) ulains

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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 pg9 mvm cn1)v9the observerm9n cv1gp)mv9 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 k-q,x*spn9ag observer. The frequency heard by the obsex 9 pk*,agns-qrver 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-sp/pt v2z4mk/. sw -pt s3gbi92 :tuqpmkeed, its half-angle will decrease by a facto4zm/mk2vpb2tgss/uqpkpt: 3i. - t9 w r 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 k x(+xbnhm g p4yo d-bvp7ys230l65rxxHz in air is 352 m/s. What is the air temperatuglxop2+06hb xy4vnp( 7x -xrbdm 5ys3 re?

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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 b)3 hd. ;)lqzxrlv4 vuspeed 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/s, a bat emits a shriek whspfxa*ssj 4 7igu-m5wg*q g1- :0ekgiw;js, xose echo reaches it 0.0250 s later. How far away was the object that reflected ba5wgxsifs j ujw-*,7a:;g m *skxg ps1i04geq-ck 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 t9u no+zg(1q z s* gt5ejw.cr+vhe 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 y(-qb )lqrl0o a flash of lightning, the distance to the lighylor -0q)b (lqtning 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 fr- 2tp;wp)qx lqom 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 deep8uwm)fqxy :/c 3y j2gh well and hear the splash 2.5 s later. How deep is the well? (Ignore air resistance, and assume the velocity of sound is 2gxjy:fh3 w8 qmy/)c u340 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 ,5i 6wfov2 exug6gukd441cmz 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 afper5q*;oq s)8 bw12 cthtwo2 t $23 \; ^{\circ}C$ 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 intensity ny)j)yvrp5z. 3d2jtlsp8 s0j yz7 je*$10^{-3} \; W/m^{2}$?

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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 70-dB wqvcfeq96s:+ v qw b75sound?

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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 ieu0(z1u 3fga7vf -crd ntensities of two sounds with intensity levels of 70 d vd0(3fr71z -fuaegcu 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 dB. What is the intensiks2ki3oe+i,8.mhy khp e3r ; dty level generated by one engih.kh2y se, k3 o+d3e;ki m8iprne?

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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 equaxdarz m-0r88x +e( qcrlly in all dr c-x0q+mdrxz 8 (ra8eirections 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 from8hv7 m ew) qz)p(d8rju a source that is radiating equally in all dir 8emu )7v8p )(jhqwzdrections 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 mWlnou kx()ju+c .d(h f+ of power, which is assumed to be uniformly distributed in all directions. What is the intensu lc)d+khx(j+ o. u(nfity 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. What wous * (nacdi.hncs( u6f(ld be the intensity level if t(.nicasd6n(s( uh c* fwo 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 60 d3fjhah(:b2s7gna l)2p a8 gxs bqwl;.B. What is the intensity level (in dB) at a).2 ;lb 3sah2agpjbn8 qfgs:hw(x l7a 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. At what distancn tw,ob42.bbz 0 pom3j(fs h.0jvzx* ye will fv xz4bbjj *t0ph w.z,onbm(2.y3so0it 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 oe 7wk9vh6 fc*yf a complex tone has a frequency of 1200 Hz. What is the frequenh9* cw67yk fevcy 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 harmonic of an open pipe is 900 Hz. What is the 8x -.j8q zowdhx+iwy5 length of the pipx.w+ -dw85xy8h jqzo ie?

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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 anv;y5o*2 xmgu1wze/m+ b 9lwvn open pipe of length L is 400 Hz. What is the frequency of the lowest tone that will resonate in an open mlx1vw ubnye 9wv*/2+ ;5ozgmpipe 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 of sofm.w 8hockb7 n)lov18und in air is 340 m/s, what is the frequency of the second harmonic? kvf o8c)78o.mhln bw1

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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 theq4/1xupd xg r j.8il(i 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 frequ54e eyxt8wu2e3: jfk9s ef*m xency in a pipe closed at one end is 330 Hz. What is the frequency of the th3j8sk2exeefx fmty5 ew:u49* ird 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 uz-.8( xt-i d npwnko.end that will have a fundamental frequency of 60 Hz on a day when the velocity of soundp x.kz.(d ut-- 8wnnio 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 is *n0/.nbeltp 7ap fvi8$20 \; ^{\circ}C$. 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 i)qd12 dt:.;ajrjif2dm5g hxx n a room 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 souna(4l6 5xi cphmrx8:, awtl f8vd in air is 340 m/s. What is the fundamental f:l68,amt f54w 8lp(hraxvc xi requency?

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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 closed onycvz- tcjj b:rwfylq 93n9wn,303-ax one end. If the fundamental frequency of w-w ztl ,c99- aqn:v0ybjyf 333rjxcn 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 emit a frequency of 800 Hz in air where the pcq58q bh otq nf qmta3v:7*1e-88jov velocity of sound 5 *n7q8m:3ae- t vhtbvoq8fq8jpq 1 ocis 340 m/s. How 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 placed no 9n*d0 d;e x now6txwp,jm1*ccm59 vside by side and driven by the same frequency of 500 Hz. If the distance from a person to one speakew pvjn**em0mdw xcxno ,d959 tnc;o16r 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 Hzuwg/5 uyfb :i+. 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 frequency of a musical ins ofjp 78 pj/v.q7fpqs9trument. If the tunpvpoj7fqs jp7.q /f89 er 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 souc63ji+e9 zi,tlb5rpaznc2d1nds produced by two horns are 6 m and 7 m respectively. What beat frequency is healn51 jdrp2aezz3ic it b+9c6,rd 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 strin h:hpy.x1z*6h 9zxgw ogs on two violins in an orchestra are found to produce a beat frequency of 2 Hz whe6 1*gx owy9xh:p hz.zhn a frequency of 660 Hz 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 stationary 1000-Hz sofqm (l7 5y(rvyund source at twice the speed of sound. The observer hears a fr(fyrl75(v qm yequency 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 (normalugx*v .v n,rn 9mxksi* cr)to30 m.mc9 frequency of 1000 Hz) approaches a stationary observer at one-half the sm n,s xr .c *tvm.ck9ivm3o90*)xurngpeed 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 3aw((7 azxd e1out/xamc.b t; moves with a speed of 30 m/s away from the source, what is the frequency heard by the observer? (The sound speed 3(dc 7w.tau;x 1o / aet(amxzbis 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/jf d.sor9 /m-,9bf vwxs on a day when the speed of sound w9/fmo v- .9rxsb,fdj 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 approachb v;c897d oi) fb(fztrha 8nq(es with a speed of 30 m/s. The frequency of the train ho c r 88fbbn;)i f(9(tzhaqdv7orn 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 you3pq h0xihf.r0 at 120 km/h. The train blows its 400-Hz whistle. Tai00.hxhf r3qpke 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 toward a stabbjr+4p6g k 6c4obf 6mtionary train. The train blows its 400-Hz whistle. Take the speed of sound to 6fbcpm64j6 gbrk 4o+bbe 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.ud*eo (vrs) 3m The train blows its 400-Hz whistle. Take te(osm )*rdv3 uhe speed of sound to 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 120 km/h. It blows its whistle, andq4k wcza eyj uun6z 0u)d4- )dxh;11qdy-0ap d you hear a tone ofdpaqjezhuyxnd61a4 0d--y401d kc uqu )z); w 400 Hz. Take the speed of sound 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. n,b 4r5ta9:.wdj wcou 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 withtnobadw4cwr,u5: j9. 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. A+z6jc8hso ct+ ssume the speed of sound in air is 340 m/s. What is the frequency heard by an observer if the observer is apsj8c +6hz+co tproaching 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 sp 6t,l ,xuzn2 ; yq u)qk0h/+halt)ufqw)kyp u9eed of an object. A 40-kHz signal is sent out, and a 42-kHz signal is returned. Assume the speed of sound is 345 m/s2uph t l,kf),h 9wq)/xlu)kzny;y6u0qa +tuq . 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 shocgu 2mf b b:8ct;m1nju/sglfoq:52+nyk 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 half-angle of the conicalvlg 9y7zbp 7a/ shock 77ylazvbg9 /p wave formed?

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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 E.;vul 00dy dzjurope with a Mach number of 1.05 where the air temperatudzv0;y0 j ldu.re is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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