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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://autodiscover.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://autodiscover.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 followin- sx2ryueu) 0ng is 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 fastest throu erxem*386h ijgh

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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 sou+okyn wi ;r;)mnd 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 happemwpcf7 m ab67.vfv+e )ns to the velocity of sound? (Assume that all other 7bf+v acv )ef m6w7mp.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 7: /lyukjx5ol 400 Hz sound, the velocity of a 200 Hz sound through air isu/7:l kxjo5l y

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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 c(9,ekl i c:k-5sq9yqh3dwye1xmtp2und, the wavelength of a 200 Hz sound idemq-ql c5iy(,e3k2w sh1:ykx9 9p tc n 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 greccc+b jfk.*r m dd;/ouu6y*j+ater 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-a4eh283 rn0 .vfu j35j 5cxbdkj enlq less 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 source is emitting waves uniformly in all d 7ikg f:0/zvpeirections. If you move to a point twice as far away from the source, t 0pz/k7fie :gvhe 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 waptyr4kd-dgkm 5z 1,f3 ves, 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 f u/y) 1nln)) +pnr,nszn: lpkat a distance d from the source is I. What is the intensity at a distance 2d from the sou)1un/s l +rpykn,z:)p nn nfl)rce?

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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 radiatingvc gbw :5:igk (z:i:+ywi5oev equally in all directions. What happens to thvgkz ye(co:b+i:55 :w:igwvie 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 soundo,jo1yb wmu n( m9e 5y8j, h:o/y*mwna source that is radiating equally in all directions. What happens to the intensity law, ,yjjoym:( /8hyb*mw9mo no 1un5eevel 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 t5u. nj:lcb,lbecomes 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. What characteristnl /l,jgyfaqn7vw5w+*x k-7pic of the sou7xn 5kqy+,nvl7p /awlgf* j-wnd 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 nsuv50jf 0j0pw :,s bvzote?

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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 tto1o6m:;f9vi 1k oqua 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 airoth;z3dmfk c) b.2cx, 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 displaceqlb* nvmum14:x6d dj);mnj 7qment 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 sound je wt;pd 31ig fjc4;+rwave generated by the guitar as a result of this vibration. What do these two waves have in cj r34;;fpg1 ecjt+widommon?

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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 4galx;f+9l uv 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 length L. What are the wavelengths of the thrqmr t 3haqw /zr-z8i+1ee lowest tones produced by this pihw8zqrza+ q/i 31 rtm-pe?

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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 pi6wwlhng9 huz3* lz36ipe of length L is 200 Hz. Which one of the following frequencies will not resonate inlh33*lnwzh izg 9u 6w6 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 freqr) .xvep j25squency. Which statemexq)j5sp .2v rent 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 is open at one end and closed at the other2-i58i 8 a6w(jh zmeh7ylox (gtxy -vh, 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 ew3h.li 1f:ns of the three lowest tones produced by this 3e1n. fhlwi: spipe?

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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 aol4 8kc,8mau u closed pipe of length L is 200 Hz. Which of the following frequem8c4uu,kao8 l ncies 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 fundamental frequency.pv+:yo1;0) ofuh nsgw8hxeu 8bu7 c9,pt(mt c Which statm9(fu18 on c ehpt );xbhu+,ypu ov0gwc: 8s7tement 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 /tj) 2xot r)nao)jl f evb(5d6same source. Each speaker produces a tone with a frequency of 200 Hz on a day when the speed of sound is 3))fb/2e6loj)avdoxt j 5(tnr30 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 twote k tifp ,)ub:75t9zpg*nqr6 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 particular beat frequenck 3;.aot b3c6n0qycdeaq 7cz5 y is heard. What happens q5z7tkc o3bcy 3a 0qc. 6adn;eto 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 explo602fev:lo r bains

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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 the o3vt( c(gs bv .3ygbu:fbserc3: 3uv(sgtb(.bgv f yver 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. ,p ,tudu ;evsw,l)yv by the obser,d v)u;.,u etwp,vlysver 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 decrease i /uyt)5v4d 9yy+ nswiby a factor of:wn diy yyt4vs/iu95)+

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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 459 eh6v8vl:(nqh d s4i o*tw6yc kHz in air is 352 m/s. What is th l (6 8ie:vct*ywhoqv h496dnse 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 7vqas(u hr :,il t+xx+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/s, a bat emits a 6l-tw4cz 7w*eqkvyl3shriek whose echo reach67 z3e4cwl*wl k tyv-qes 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 teggw1d j5ggzx a+/b(z l(,7esuxm;qg 6mperature 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, the dist-wgis04:-au rdv6d ia :snll2 ance to the lightning strikeivsad us:nw-4:ill-a02r d g6 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 tempp2 e sxx y8r4rqt1m/n erqf059erature 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 he/ea 4wn9n ;bpnar the splash 2.5 s later. How deep is the well? (Ignore air resistance, and assume 94n/an ;pe nwbthe 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 ay)kis1 pdkg9724 hslof 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 air atev-x2zl9w*; 9u v clwg $23 \; ^{\circ}C$ 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 l; wsp)hxt f2 sfi7tz* ez d,;mbh5t:)mevel of 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 of a5hlyj 4o6:s d;hv)ip w 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 two sounds wit q7wd fvdt;0il10y on8okr8 j8h intensity levels of 70 d7n00f 8 ow8;lordty 1qv8jdk iB 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 engine+pw /.slp;jkxh* np*ls in a garage is 100 dB. What is the intensity level generated byp/nklwp xp+ ;*jh* sl. 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 isssjxs61ra e1 5 radiating equally in a51r6sxa j sse1ll 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 distam ;8pqdqywo40 nce of 6.0 m from a source that is radiating equally in all directions i;md4wp8q0o yqs
$6.0 \times 10^{-10} \; W/m^{2}$. 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 powepeg mkws(7:q:n6-zu j r, which is assumed to be uniformly distribut7sgzun w :(:ej6q-k pmed in all directions. What is the intensity level at a distance 5.00 m from the dog?

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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
教师可以抽题组卷或一键复制本试卷，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
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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. What7n45v boe b6/ocpucn;x3 v)s t would be the intensity level if two identical dogs very close to ebc v5;/ o 7e3)6nxcsuv4 noptbach 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 + 2f6)s *p,kmx0pm.s yx g*y rmuybe 6ekz-.cx60 dB. What is the intensity level (in dB) at a point 2.0 m from t6mgbse m*,kk xfp62y szp) e-.x.*x0 mycy+urhe 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 d6 m9do;uc / 5nh,dl *bjg bpfhs3nxo;3B. At what distance will its6;3bn5, 3l mnogphf*;xc/ uhbodj d9 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 oule4(m2* de s90jj9 kclbr pm5f a complex tone has a frequency of 1200 Hz. What is the frequency of the fourth har 0rls5mdk(jbc ej2m*99u4 epl 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 augww49x+ sofl d4p l((n open pipe is 900 Hz. What is the lengtwdg9uxlpf4 lw(4s ( o+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 isp ,fgbe66rcwth4, al0 400 Hz. What is the frequency of the lowest tone thchebp ,6l046 wtrg,afat 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 . atl:) nb6y4araj3ks0.80 m. If the velocity of sound in air is yast34n b.aj)k l :ar6340 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 whe*gkfl2 q, v-bzre 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 im*c s2.2ga iph. vzg3one end is 330 Hz. What is the frequency of the thirai.g sg*.ch23v pi m2zd 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 tmui- al ni(,i01 rxho*r,ia3 g5chyw(hat will have a fundamental frequency of 60 Hz on a day when the velocity of sound is 34c nh liiwr, -xy50i3(gaiuh 1*rm(o a,0 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 i50 t5uiz(tcpc ua8 ;wgs $20 \; ^{\circ}C$. 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 te/48zch+,owsp v. r vo-upf j2rmperature 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 03d oxqdu) ( w0id4 tw-legvo;the speed of sound in air iswo;tu4d 0i0-de( lx g3dv)wqo 340 m/s. What is the 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 same length: one is open and the other is closed o qyxbf9hc q hl2)l/((bb)um rhuko*;/n one end. If the fundamental frequency of the open pipb(l2o9fxb)khu qlr (h);c ym qhb*u//e 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 velociit*clk) ,, ax:hus. o,z1 mqe22tvhqsty of sound is 340 m/s. How much farther back would source 1 ,a2.:tc)eth m oh q,kqu*21,ixlzvs s 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 of 50tu7cf2q(pa f*fl wf280 Hz. If the distan pfw(l2t cfu7af*f2 q8ce 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 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 Hz. Wdu6)62pkb (vv o fp79dfj;vtj hat 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 mpt4-5 hiyxeo pjz9 t g9)x9x;qa+ qbs)usical instrument. If the tuner hears a beat frequency of 2 Hz, what is the frequency of the insxie+9 9bgt xps -q;a95)4opjzxq)htytrument?

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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 and 7 m respec.zyb-oku orl -dy;4w (y zw2+ttively. What beat frequency is heard when the horns are sounded on a d+ry4 yktbwdoz; --.u2z (olyway 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 an orchestra are foun)) sh hh14 ywfa1lm-hhd to produce a beat frequency of 2 Hz when a frequency of 660 Hz is played. What percentage change in the hhm)1sa h-wyh4h l1)ftension 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 t2rlrp u bygb 3.knwe9:.4 mi/speed of sound. The observer hearugtr n9iymb .4w3 b/.krpel :2s 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 q1v-grh/h ewj,zui)z 0c) 0fea stationary observer at one-half the speed of sound. The observer hears a frequehv erhg1j)-w 00 ,euc)/qfzzincy 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 awv 83)ikn+qwun/vv3ip zcp- ( listener moves with a speed of 30 m/s away from the source, what is the frequency heapvnicvw8p vz +-nk /(33 )iquwrd 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 35 mfu1a+-8 2jz:qevnlhs /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 frequency does the observ-: u +ajf1 2h8nslqzever 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 approachj,n 2e98py/l d u1bwdfes with a speed of 30 m/s. The frequency of the train horn is 600 Hwypdud8/bj12 fel9 ,n z 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 12 pan 7w1ndn98q0 km/h. The train blows its 400-Hz whistle. na wn9n78d1 pqTake 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 toward6 n4f( qky+janevm p:1 a stationary train. The train blows its 400-Hz whistle. Take the speed of sound toq ymfn(a: 1k j6pne+v4 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 1)tuir v// czy/20 km/h. The train blows its 400-Hz whistle. Take the speed of sound to be 340/r zt/yi) cuv/ 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 8 qa9 kkyjo1jwvsj .ljb- +*j5away from you at 120 km/h. It blows its whistle, and you hear a ton8k9yj1 j-jvabjo. 5 j+*kqwlse of 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 r zz:,3ipi t( h+p5/+wajvskois 500 Hz. Assume the speed of sound in air is 340 m/s. What is the frequ +3jsw/i5 voaz ,:zph+tpk(irency 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 t2 sb; zkglfmj55 rc8,500 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency sz btrj;5,2k gf8c5l mheard 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 o jw*s/h8htj2q+*uv d-uk2cn an object. A 40-kHz signal is sent out, and a 42-kHz signal is returned. Assume the speed of souqos ducu /j w*k*tj +v-228hnhnd 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 prx uuoa yx65inu+7kb58y zn:0)gxh4(yi m)gi t oduced 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 conical shoc5.pd(n hfx f(ck wave forme5xpd(.(h f nfcd?

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Concord airplane flie0 o8:mcbuhuj*na3w7kp d0a )ss from the United States to Europe with a Mach number of 1.05 )7wka 0 0 u:copdu8n*a3h jmbswhere the air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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