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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 is av-f 0dlxqq ng;oac 815 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 conducojz-94azmo 7 xted 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 soun;f r/o.yxr)6 ucf 2yb 6qunw-wd 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,n/dqy:uvl )vks/3(ja what happens to the velocity of sound? qlduy( kav/3/ :jn)sv(Assume 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 sound tdktxz /xc+k3v /vid0,)c+1 a5ukrzp lhrough air0r1dvxzidt)p3kac /x +l5u +kc/ zk, v 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, t b 7:z1aaafk*1exruxcv(*sk(he wavelength of a 200 Hz sound in air iv(* c*7s uzxaaxa(1f r1 kbek:s

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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)zd1qjp 2x ok, 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 20t +j2zet s-tlc4- 1goo-8f qcc 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 sound9fve rge xg/l9(xs-3we uo8g1 source is emitting waves uniformly in all directions. If you move to a point twice as far awaywe xgoesrf 9(8eg/lv -9u1g3x 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 i2ctzry74c3kabb8- ln s 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 diswk lb97j4+/c,ot edldtance d from the source is I. What is the intensity at a dist dletb9cjl,w+k 7/do4ance 2d 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 dist5c- jjwta4g9q)bl+.t l3b fh.gy2aerance from a sound source that is radiating equally in all directions. What happens to the intensity of the +a 5tjb h .fa3.t2) brl-yge9 jg4wlcqsound? 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 aitpij5sos3x47 6 7umm sound source that is radiating equally in all directions. What happens to the intensity level of tpu3jx 7 s7io5is4t m6mhe 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)1s 2tqis0bwt der?

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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 emittq:g zl-kozw8t b0(ib 8ing a pure tone. What characteristic of the sound increas-iz ltwz bkg8q (b8:o0es?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What determines "loujzs7 gn8r r8g.dness" 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" of a musifu1c-q/wpk3/hv tb9 hb- :udical 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 inspfxzvniu;:94 otcnx )):r e7 to 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 l51 rrncjz3 5fwaves 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 guitarcqpfwuu 13/*z string and the sound wave generated by the guitar as a result of this vizwqcu3 up 1f/*bration. 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 both ends, tr 42 p,kv-v6; ebaad) ifkt.cohere

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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. mac8: (yzfqpn ,a 6qnfk.8y6*3tzi vc What are the wavelengths of the three lowest tones produ qf*nyav8i tm6. 3,pf8:( zy6ck qazncced 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. Whichgaw09alhk :5d one of the following frequencies wildhag0a: 9l k5wl 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 resonating at its fundamental f+m5 , psc(rl g;mlejq,requency. Which statemente+ qmprc(5j;s, lg,lm 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 in3)hbu3bj ls v hg5ks )71dvb.s open 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. What are the wavlfixwq;8z*s,gc tq( /elengths of the three lowest toq*8i(xw fz/sc;qt l,g nes 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. x:ewq7a*pcm( ikxwo+4p2e g ;p3v rp9 Which of the following frequencies will not resonate in that pippe qva xk;ce3 *7o:pr2g4+p(9wmpw xie?

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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 closef g8k fkd7vg72czc8 7vd at one end is resonating at its fundamental frequency. Which statemencv87gf gk f8dkvzc277t 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 a qn+)nfe1 t,v 3etzw9speaker produces a tone with a frt9qwan3nef t)evz,+ 1equency 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 bo:buc uy-+gi b5qw4 *seats, 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 sounded together and a par+gd3udyy :n+ f.t d 9+wq *xsjbxtqo4(ticular beat frequency is heard. What happens to t+dy4g.wutf3* +tbq x9jn (dx d+:sqoyhe 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 ex;,sdq9qw9 ms.h*/cei fw j0) rct -cfnplains

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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. 4sf*fmezo:x.95ah8o v9kz wjxtip3 6 The frequency heard by the obsw m9 f*3. i 69v8k poxzxohjaef4tsz:5erver 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 2je bcn kc.r(n+l7qp;hw6 4nb by the obq( 4rncnejl7wb +p;k6n.2c b hserver 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 bt5u .9vqc6)4stfv1sh8v xa;h ;t ly8igb ,u ewill decrease by a fei v8q u;s;5t4blvc byshvt6g.1u8)t,h9f ax 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 ie*/76dz)qooyxes dj. kp:ov*s the air tempe)/xj y6qk . o*zedv:d7sopo*erature?

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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 s2fcevffqz/t -a2a; 8at, dcw2peed 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 ivan0k 5 7nu+nwn air is 340 m/s, a bat emits a shriek whose echo reacuk0vw+n na5n7hes it 0.0250 s later. 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 in 4.00 s. The temperature i*s-)f.nt:a,b gawqs rm /7m mds $0 \; ^{\circ}C$. 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 5l (8iauextqd mb, r8.0.0 s after seeing a flash of lightning, the distance to the lightn,txura.m0 8eq b(8dil ing 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 nhnqqfzta 6 lp14 7:5ws from 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 splash 2.5 s later. How deep i7jvp/ yt2v76r orkx:k/r bw*;p pvy x1s the well? (Ignov:px*26p 1o;wxr/7 y br j vktyp7/kvrre air resistance, 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 freque;4d2ullgu/y hu 6f no x/;sph*ncy 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 armzs )+u7(r k:. iity8llojx6ir 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 sound with inte.bazgu iupx4;q9 ;mm0nsity $10^{-3} \; W/m^{2}$?

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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 vk31lu)url fil9- t, cof 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 intensities of t nxryqo4. 6o7zwo sounds with intensity levels of 70 dB and oo7nr. x4y6zq40 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.4o *3hi qkjn:l7dth va;h uh6r.j0 uk8 What is the intensity level generated by one eng7 ;.3a j 0lkohr*:nhtkuu68jhhv q4diine?

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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 sourcemj,7iuzn9v o:8le l: y that is radiating equally in all directio: vyij97:ln e,lomz 8uns 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 thatv)xsbe-x yxb d:5o6w my-6gq8 is radiating equally in all dir-)wvq85e:gsyxb-x oyb m 6x d6ections 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 off3++ toa* /:v okabaof power, which is assumed to be uniformly distributed 3f+abv*aof : +/ok toain 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 wok*m5 umvz87.u9kmb dB at a distance 5.00 m from a barking dog. What woul u89 mkm*7muk5ob .zwvd be the intensity 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 iuv v1k- fi.8;j1( hjrak73fxh .xikun6xu 1lps 60 dB. What is the intensity level (anf ul6khuk. 3hx1vf;rju.p- jvxk81i7x 1i (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 h5bqy b,-jw-w is 95 dB. At what distance will it be 75 w ,qw-5hyb- bjdB?

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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:h )wkfmvk8l0dm)aikd / 6 e1b tone has a frequency of 1200 Hz. What is the frequency of the 0fd/ )6:i)dakklm h vkeb w81mfourth 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 th-ti.g*u3)zoo 9nzpoxb)h (qu h rt;.o ird harmonic of an open pipe is 900 Hz. What is the lengt)n*br () otzhuxhgi oq3ut; op.z.9o-h 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.kitt,0w6cwr ;g3 um :u What is the frequency of the lowest tone that will w6wr,m;guut 0it3:k cresonate 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 bp gv4 -dz9boun3+ lw/voth ends has a length of 0.80 m. If the velocity of sound in air is vb4du3 +onw-zg/v9lp340 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 ing (b7zpf idt3fdbs*xf5/ ov *9 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 piaw 8sai 31m:.i/nv:0kx:ho7hesrhs ppe closed at one end is 330 Hz. What is the frequen:v nrpi/ss 8h.x maks3eh::iho0a17wcy 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 end that wilo28gcgxrpm+ / l have a fundamental frequency of 60 Hz on a d+g xom/cr8pg2 ay 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 whemj(n p-i:ho;qa -, 0bse+ovqjre 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 n nh2qtsu7 v9d3tt3 ql+t(ts(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 wwc;ajhpmnfx v;vy-5l6m;)2pi d, x+ y hen the speed of sound in air is 340 m/s. What is tvldmv-jhc,yi yn;2x)f6 ap5mx;p w;+ he 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 yg/3 pt);hqwr same length: one is open and the other is closed on one end. If the fundamental frequency of the open pipe is 300 Hz, what is the fqywgrhp t/);3 undamental 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 u.69:x ayql.hq mosr )a frequency of 800 Hz in air where the velocity of sound is 340 m/s. rq6.ulo y9sxha:q .m) 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 plab3cuy.dv 5f lquk(- k5ced side by side and driven by the same frequency of 500 Hz. If the distance from q3cdu- bu f5 5k.(kyvla 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 freque9 ghu8b)eog5 n3 ojl9pncies 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 t)5ozw;)d eawsq7tq- o o tune the frequency of a musical instrument. If the tuner hears a beat frequency of 2 Hz, what is the frequencw;o)qdeos75z-twq ) ay 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 yp59a n1ac5zd2y.y paand 7 m respectively. What beat frequenyyzya91 c p .52anpad5cy 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 vio2(bgoyv j42a:z*slxquh3o/1-hkx k0j ) awek lins in an orchestra are found to produce a beat frequency of 2 Hz when a frequency of 660 Hz is played.0o k:a(s uybxvk2j g *l-we)4jxak/h1hzq2o3 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 sound source at twice the speed ome6 6kflm8 -6rz e-mvnf sound.lv 6-m f8k66 e-mzernm 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 oq nra; -ip12chf 1000 Hz) approaches a stationary observer at one-half the speed of sound. The oq;n12arh-icp bserver 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 Hagvrjt,6e5/ s9db do bmr2k6 ,z. If a listener moves with a speed of 30 m/s away from the source, wharvdmdj6bge2bt,6,/9 5ro s a kt is the frequency 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 traveling at 362t d/yz.fi(n hvw 6mt5 m/s on a day when the speed of sound through air is 340 m/s. Thhizt6t(.d 6/n y2fm wve 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 sta)lrp*w4cv*o +tdu-x j tionary observer when a train approaches with a speed of 30 m/s. The frequency of the train horn is 600 Hz and the speed of sou*c)xpl- ut +j4 dvrow*nd 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. 2l4*tru k-dnt l0,lsdaxz1q/h. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequend nultlz1 .t, rd 2-ka4xs*l0qcy 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 train blows td 8ua2mfdiu5rf35d5 its 400-Hz whistle. Take thrudtfd5fu i 85amd 352e 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 its 400-Hp7slcmq cp8p0x q0-57o j 3qxpz whistle. Take the speed of sjpxx 3 0-7 pscqp5mqlo8pqc70ound 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 9g*5+xrlkrn q from you at 120 km/h. It blows its whistle, and you hear a tone of 400 Hz. Take the xrkrnlg5+q*9 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 i2g)l 2qgxeu(tz1( 86 jkyls31rb d.a /h fjnfHz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by af(qz 3 aiu (gfrdn61t 1y8egs)jlk.bx /lj2h2 n 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 50vowcz:l.kd2 gc37n:+o poxh -jx95 yu 0 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by an observer if the dyljxwvg7uzkh+.op9x23c:5c o: n-oobserver 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 object *bb effudj6j(qfdftox.k -2+ 6v9,pq. A 40-kHz signal is sent out, anvdqff+6j* f9,pkq x -tejfd(b6u2o b.d a 42-kHz signal 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 supeged ,i(5gr7n-x, ,owv b;xwsb-0 ujbprsonic 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. W1 ighepgf.kc3he ;jp77pk8p med*4- ahat is the half-angle of the conical shock wave g*;k.-ed7ijkhcp me4 8a f 1ppg pe7h3formed?

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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 Uniteyapb p s3d-* n*sib5*m w5, i,rzzqu5xd States to Europe with a Mach number of 1.05 where the us,3aziq*d5*,b*ypn- izxmbps5r5w air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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