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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://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://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 fexdd/g8o*8 ,q gkin7false 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 conduct +vw.p(vkpqwrur ib.brye)q4 *2/ xx) ed 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 rodt*0m5oeb guoeb+6(mw p4o5py?

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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 velocity of soun zudi -;9*d14disvsyjd? (Assume that all other factors remain constanus*s- d;dv1jy izi49d t.)

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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 souznkryb 6wb ,./nd through airz.n/b6 yrw kb, 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 sour4p-ihv()li. sp j s14meh e,mnd, the wavelength of a 200 Hz sound in arp .sii),l4mjvhs- e(hm 1 ep4ir 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 freq qrphz3/tr* 561 :+ gfrbrrvqluencies greater than 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 less than 20 jywae4-x jq :y2;)jc iHz 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 ps/xa05xsstf7)t(dvq63hl (d ks;llwq +cg 3 uniformly in all directions. If you move to a point twice as far away from the source, the frequency of qvt s5f7s(wl) x x 30clq pd6hs(t;lgd+kas/3the 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 4 (lvof+utwgi44usj6is 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 distance d from the souru82x b/ xl*cl8b.dozcce is I. What is the intensity at a distan8 c 8/xozlbc.ldxu* b2ce 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 distance fromy)x:18o 44fatdl 7vxasu lm( f a sound source that is radiating equally in all direc la1) udftyomvx47x laf( 8s4:tions. 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 *f(ruu6jb3lj d h 8cjxce31f5sound source that is radiating equally in all directions. What happens to th8 u5f3cjex3r huj *jd1f( b6cle 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 incr(ql wq.g-z9u m* xpjnmwn,k *lr+ h:)keases as a 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 pure tone. Wha6xz793ysl m pa08m/lk-ft er +np;sgwt characteristic of the sound increasm 6wp9a0/8 ss+7elkz p;3mlfgx tnr y-es?

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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 note?7bl5ey/3sw:bw p 9 ecg

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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 musical note?tj x6kg w9af(i*5q5r e* +otlr

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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 g1ad.mcy+9qomucoeb.b --n 7 c,n2uuf. ol x8into 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 zph.yq0:n kw+)r pqu.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 2v7z4q oze a u-bnif8k,lfq 1o;a:wj)by the guitar as a result of this vibration.aj;lnvb4z2q-fao,q):uw8k fie o 7 1 z 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 whic/dh/ pn3c vhgy2z(a;sh 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. What are the wavelengths of the three lo0rh* xi9w7aoh xz 61rowest tones produced by this piw7xhi6* za or0xh9 ro1pe?

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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 resonatk- 1 t6rw-xa-c k6gkxbe in an open pipe of length L is 200 Hz. Which one of the following fret6 kkcb-g1x6--rx k waquencies 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 resonating at its fundamental fkym7:v pw ))8tnpal; +youvk 0requency. Which statement is cork)v pu8oy):tvp ywknm7 ;a0l +rect?

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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 and closed a3.s,+xqhcj7 jn/ey6hi3bb a nt 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 three lowex b 4nj;;)di agq/p :qz3lm:bjstjbpi ;q m lqb3a;:ngd:z)4/xj 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 in3j0; jri ez9 bl*ndtp. a closed pipe of length L is 200 Hz. Which of the following frequencies will not res; 0*rbp dnl.jiz ejt93onate 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 fundam5;ym)4 (q9kxkkb2jxv we yjxcm 8i1 6f+zto8w ental frequency. Which statement (cyxwt xzow;k1kj2f qmve bk)5m yx84986i+jis 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 th(d; soc5tnm4de same source. Each speaker produces a tone with a freq5c(4 ;otmdnd suency 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, :2dosa 4+mjjr 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 sound-a u:lvzd3;sded together and a particular beat frequency is heard. What happens to the bl dzvu 3ads-;:eat 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 expli+c x+x1 zucoz h0b:;hvni:i5ains

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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. b0kp737kci5pna7z*pa dzt v+ The frequency heard by the observetz3nd7v 7pi05 pabzk*a+ 7 ckpr 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 hearoxd -z+(4 wz djw: :kqi33nqcpd by the ob( ix4w wq:- zkc 3o:njd3pzdq+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 tnpw5 5m6ln;h)* ej shno double its MACH-speed, its half-angle will decrease by a factnnewm;lj* h5s65 )phn or 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 ultrason :dbs*i 2p2rinic sound of frequency 45 kHz in air is 352 m/s. What is the air temperature 2:dis*b2n ipr?

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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:mjo*bi+mtuwc a*hev f b r/ im*.31v0 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 airthux+ru* fx:ap7c17y is 340 m/s, a bat emits a shriek whose echo reaches it 0.0250 s later. How far away : thc7f* py7xa+u1ur xwas 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, ank3e + tx- +7dkmoo0wndk:;ww wd hear 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 lightning, thct.on:iyc +5re distance to the ligh5y +o .ccrin:ttning 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 from a cliff on a day the temperaturw/u9 yewru-w9p-aiu t: 7gkb4e 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 de3 do,o dxl+io(e9okop vqkw)+ev)a.b.m5si 2 ep is the well? (Ignore air resistance, and assum)oo9ovq,x.m+ie spdb)+ia w(e 3kk.2 l odv5oe 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 ofmu+.5 ec ppn:n5tvj,z a sound wave of 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 aicp8gzx6 fpnl8e1h4v gk7-a*o r 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 4wg71zvl3 ay)g(tugfaf/* pj kx/+r lof 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+ q ;2.gf c jcul/h4c+12vuzqc kqguy; *jnkt- of 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 inrfz2qy42 b(zvqsi5d 4 tensities of two sounds with intensity levels of 70 dB bqzv4 (d2f45rqs yiz 2and 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 intensity /rhtby(p- clwb j3o25level gb2/b(hp- y 3colwtrj5enerated 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 v)zdrd/wvnjv o1:;8i of 6.0 m from a source that is radiating equally in all d1vo:d8/ j;iwzr)v vdnirections 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 9h2jyvi:f1si source that is radiating equally in all directions jhys9:i2i1f vis
$6.0 \times 10^{-10} \; W/m^{2}$. 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 u ui8y *7uxpnipg9q;jx /3vy7d niformly distributed in all directions. What is tnqg8iyx7;*/ ip 7j9px3d uvuyhe 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 d3:qhuga :;eh barking dog. What would be the intensity level if two identical dogs very close to each other are3q: guhdeh:; a 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 inten6 *;nbatv+e :ubxfw,xq e tn1*sity level is 60 dB. What is the intensity le, b*w1 ebfn+6 q:n*te;txuvxavel (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 levelye4 .xy nah 47d2ns6zw 5.0 m from a point source is 95 dB. At what distance will it b4zn 2x4 aw6yy7she dn.e 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 frequj;n* /wrm xr8mzud(5wency of 1200 Hz. What is the frequency of the fourth harmw;5rnmd/(uw xzj 8r* monic?

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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 lengwd x-6l;zedyxa3k6 oyw j 7a45th of the pi xz6x;y375dayo4j6dkl ea- wwpe?

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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 t054gbczy (j5fkl d-b length L is 400 Hz. What is the frequency of the lowest tone that 0 jzt fby( b45lgd-5kcwill 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 a tu ;ab3 fb0w0z:hpj32xcf/wqt both ends has a length of 0.80 m. If the velocity of sound in air is 340 bujf0;2: 3wwp baxc0 t f3/zhqm/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 tfb./)o 4- gmg z/dx*yja.jszshe 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 6d)il 2vbelzhz -+3jz*g i/wz330 Hz. What is the frequency ofgzhzi +lvlw ze*d62i- )jzb/ 3 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 pobgx1c/) h:rj w:pu,v i.hz; nipe closed on one end that will have a fundament,1c ) h g:p vn;.oxrubizwj:h/al 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 where the te 7d6qy uim k*or-03pjme1 ;wxemperature 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 is6xih/.ybkgr.vglx xa ;z*;j6 in 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 ss)50ir4l h3ga.r p ygeound in air is 340 m/s. What is the fundamentag rgly iae s)rph3054.l 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 cfjs za l-s9;61(v tgbclosed on one end. If the fundamental frequency of the open pipe is 300 Hz, what is the fundamental f1 c6a;vbzs jlfg ts(-9requency 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 emh12 aheg-j/d,nzk sf0it a frequency of 800 Hz in air where the velocity of sound is 340 m/s. How much farther back woul njd1f,e hg0szk/ah2 -d 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 side by side and driven by the same frequency ofd+a y)ehp3 0u 9fuss -wvf6.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 poufdysovp )09 3f.s+ e awf6uh-ssible 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 443p 9 e 4,buy;oysgc-bgrfz-y60 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-H)kt d.hf95r-rss0j* 7d 3lyxkflm) uv z tuning fork to tune the frequency of a musical instrument. If the tuner hears a beat frequen9.d r)ft7 u* 3fsdms-k jl 0r5vkhxly)cy 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 produce. (p nmsau3q1jd by two horns are 6 m and 7 m respectively. What beat frequency 1ps.umn3qj( ais 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 i2/q/sni3xe) vlejp. sn an orchestra are found to produce a beat frequency of 2 Hz when a frequency of 660 Hz is played. What pervl2 j ns/pe3)qis/xe. centage 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 sps4zkk9)- hzrbeg0q.b eed of sound0.sb )hrzz9bkkg- 4eq. 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 staf s, pjv1u 3(26nif2 ubyvvtm+tionary observer at one-half the speed of sound. The observer h (vs2nymtfu vu +,63jvpbf1i2ears 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 move 0f1b-z(.rr+ kfiq ogfyp 5yn2s with a speed of 30 m/s away from the source, what is the frequency heard by the observer? (The sound speed is 340 m/s.fgq r 2z5(p-yok1rn.f y fi0b+)

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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 809(l4ve ncj+t k0-Hz siren. It is traveling at 35 m/s on a day when the speed of sound through air is 340 m/s. The car approaches and passes an observer who is standing along the roadside. What change of freq+ncvt9 e l4(kjuency 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 approaches wit; znup*zen, ,mj++ vgsh a speed of 30 m/s. The frequency of the train horn is 600 Hz and the speed of sound is 340 m/s+v;j mn,+e*suzgn zp,.

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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/og8m wpw0ub , 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 hearw8 um/obg0,wp ?

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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 3oe4(ehfut ;(9v fyjytoward a stationary train. The train blows its 400-Hz whistle. Take the speed of sound to bh vt( ;93eo4ufjyye( fe 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 jahx( p 3-y6 .ravnn-nat 120 km/h. The train blows its 400-Hz whistle.r vna -3a.(6nx nhp-yj Take the 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, a,g m zy ,j hrffkxs1,yhl,*0)5bhm,vy nd you hear a tone of 400 Hz. Take the speed of sound t j fglxy, hvb,ks rh5my*0z, y1,fmh),o 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 Hzqqs 6x;(o cap7. Assume the speed of sound in air is 340 m/s. What is the frequency heard by ansx poa 6(q7c;q 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 l :hk+yl2y n(s,j82jdjx,hn xis 500 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency hea y2ksxn( ylhnj+8 h2:j,xd,jlrd by an observer 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 speed of an object. A 40-kHz signal qi0thc xt l/ 4r0whj)n,:d1mv is sent out, and a 42-kHz signal is returned. Assume the speed of sound is 345 m/s. How fast is the object moving?0cmq hrxtd 1n,w0j: )thil/v4

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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 proiyt-n zxchh r;4up3 -+rhk2a 4duced 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 tp0psp z(4-y9 mi4ot/7wb cqdflc-2j qhe conical shock wa p0b 2jspcd/zt4cm9 i --4foqq(lw7py ve 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 flivpr wz2 lasjroez/;3x/0pj .*jefg0- es from the United States to Europe with a Mach number of 1.05 where the air tempef g/-j pop3;xe .zz2a00wer* l/svjjrrature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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