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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 a fajq:51azr z q966r xiarxs nb +y/z0iu/lse 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 con9tk1: jd*1n w,wl6pc(mdf dsmducted 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 /e3rdchm+ 0 97sd a-p0faguuk 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 happens to the velo;(l )b3y ymc.4udz ogecity of sound? (Assume that azy;degl . 4om3bu y)c(ll 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 txc/o: d w5 , ckv*b*o8j9rrm7jlxw;3sgbs)bk hrough air 5s/xb wck)*d7bj*;,csw mj l8 :rvgb93xokrois

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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 40za() 9st. w98pu6+9m r+xidihmho ighjo40pl0 Hz sound, the wavelength of a 200 Hz sound in air zo 8 p099lj+ o4wsm9ur(dm. hhia)+6h p tixigis

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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 2j7bzz(dmcji 26gh4cp1* o cw +0,000 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 frequen 2 s,6e4ebw ii8pn3mlzoeg ,k9s:5 zizcy 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 direg6d v- qlm. 1/ibqdeendb08 z0ctions. If you move to a point twice as far away from the sbd gz/6m1qv8e-l00deb.qn diource, 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 is pro li8ow,i.h:4/ oq fdhgportional 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 source is I. zms;; (d k/lej What is the intensity at a distance 2d from them dz(e/s;; jkl 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 tha0-* ;q3;l2wedb xa h upihdg/jt is radiating equally in all directions. What happens to the intedgbhu ;3 xei d; q-j/lha*p0w2nsity 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 sound source that is ra qoirtxjms:;e3 n8j.m/d zpn 5aor2ds, 11p3zdiating equally in all direct;rsj:1 mzdmr .5q1ze3j8ons2,xpanti /d p o3ions. 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 iju025wea qq d3ncreases 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. What characterist. al* aos4 ;l0hwpzha/ic of the sound increaseso;a/azsp*l0wahh. l4 ?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What determines "loudnes*7ys/alp,tlf9 p dftcux 8( f4s" 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 musical note7xk0 rwbaly i2:(0g2 ksl:ua e?

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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 wath hp,oww*;3 s(d *os-hd)jvvoer

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displacez1 7n2olf;vr hment 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 waves.z*jf4,;zi7 kdux cfy2vlr* generated by the guitar as a result of this vibration. What do fvykc.l,d jz7xuzif*r4; 2*sthese 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 bot-dmp+;m /xbran( zh 3lh 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 a;dpe n ul0c: 4 s17a0cb5rsutzre the wavelengths of the three lowest tones produced by5d:sc 7; t zleuc0u1a0rpb n4s 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 azhr)hsb.(g5of length L is 200 Hz. Which one of the following frequencies. hzg( h)5bras 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 itspgzkdha0t:,zhc 0 :v2 fundamental frequency. Which statement iph,v 0g0:z:d2a kthzcs 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 ope, f:9x5q +xgyihl.oyc( bf ln6n 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 wavelengths of 0 4hid ca+b5ckt 0u;o0flm 7 j*0yycpdthe three lowest tones c 70bl*jcyd c+ yi054mfdtk0o h0up a;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 lengtt4k p*pr0fk zpee;w:1h L is 200 Hz. Which of the following frequencies willpep:f;e*t k w z40r1kp 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 0c7:(k udf3chp izsk- end is resonating at its fundamental frequency. Which statement is c-i c7 sd03c:uzhpf (kkorrect?

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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 s*zvih )5l z(tlame source. Each speaker produces a tone with a frequency of 200 Hz on a day when the speed of soundl* htz )ivl(z5 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 beatscop15*pa4f 19u8es hwytga z .tx4) ps, 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 souxrnmvb19fd2t6j/ s z* nded together and a particular beat frequency is heard. What db9 ntr*x/fz1mvsj6 2happens 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 explainsu gfre9p -,zn( *0*fpjc-c ,s.dhuazs

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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(u*ez 9b et)hja3y/wn 5h rkl7 a stationary observer. The frequency heard by the obserb(r9w /eak u 3zj*hnt5h) yl7ever 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 o*j7 mbrm6uv(ce, eom*n t o 3uzz*0e4frequency heard by the observeueb* zrmnetu moz e co4m7,0j3* vo6(*r 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-anc h1f66xw,j) f1xwodkgle will decrease by a factor ofxf66 kf)w1w1cd jhxo ,:

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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 wzd+zsws:n 9 j)yz1n :frequency 45 kHz in air is 352 m/s. What is the a njw)w 91zzynss:+d: zir 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 o +n0u-af ja.irdvmcg:utp 7a :8cq+/eb,exd. f 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 ofmiu;ro; u ubn7*e o0i/ sound in air is 340 m/s, a bat emits a shriek whose echo reaches it 0.0250 s later. How far7u enuo/*;rim;iu0 o b 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 2xc2m6ng 7dr i ce;lv.dj:lra- : d;mbs. 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 w3 /2b(vjp:lmdywqy/go (gt-lightning, the distance to the ligh(y :my3 wl2tqgjv-wp (/ /dgobtning 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 dag552wbc,ao0:*nh zg z* i onxzy 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 later8 i s;h o9v:jqzqv)55k1 ;qkila(werj. How deep is the well? (Ignore air resistance, and assume the velocity of sound is 3aovk rs; q 95q 1v;qe:)z(8i 5iwljkhj40 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 oqxpdc rj-35d) 3obam)f 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 atl* -s7r -y*o.a h wi6coh:shlrrv44r g $23 \; ^{\circ}C$ 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 n2935ss +q/4qscf fw ug jmpp.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 sls99 jj*r r3ul1zuj+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 intensities of two sounds with intensity qo-;;a,86m sx,wrcg, v dblxnlevels of 70 dB and 40 6 xorx;,q dnl,,vbmc-;8 agwsdB?

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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 garagid 8vm(5ev wm0/cr 6cwe is 100 dB. What is the intensity level generm/m 0vc8 5 iwwe6cvd(rated 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 discg;w 2juk;4 9pj+sh (;psmbvq,h9 xyk tance of 6.0 m from a source that is radiating equally in all directions isq;sj 99mhjh xpk,(p;cvyg2; s4kuw b+
$6.0 \times 10^{-10} \; W/m^{2}$. 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 ta 4b.ku83xxsihat is radiating equally in allia.8 xsu43kxb 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 assumed to b,y/v8ikgb3g ce uniformly distributed in allcg8y ,ibk/v3 g 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 m5nqzx*bu 7n-eok;m 9uzm*g;c from a barking dog. What would be the intensity level if two identical dogs ver;ge ummzb9xqou5 zc**nn7-;k y 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 sou:-sw acpa bapn,t4 8v9rce the intensity level is 60 dB. What is the intensity level (in dB) at a point 2.0 m from the source? Assume ,cn 9awapsbptv- a:48that 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 y u70rnnw+ur,. At what distance will it be 75rny ur+u ,n70w 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 frequency of 1200 Hz. What is; yq4:cljt7wf the frequency of the fourth harmonic jfq;t :cy47wl?

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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:qa3rvm+3ub- gumfx/hi 2/us Hz. What is the length of the g rmbm/a ui/:3h2+qf xsuv-3upipe?

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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 (q* kj (zk/dgzlength L is 400 Hz. What is the frequency of the lowest tone that will zz gkk jq*((d/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 lengvop f16j6np*:;pne b fd:yvu 9vso,h 4th of 0.80 m. If the velocity of sound in air is 340 m/s, what is the frequency of the second haeysvv9vf * 4;,o66joupfbn dpn1: :hprmonic?

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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 the t9g0uk0st ( ekoemperature 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 n+kg+8 s6ubgm yriw (+pipe closed at one end is 330 Hz. What is the frequency of the thiy +g+68ng wmbu r+k(isrd 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 *xgjb4ar k4f5nbj4bnfk:5 )a 4y g bh.one end that will have a fundamental frequency of 60 Hz on ky4bgffgb4)*:. knrbbj55j x h4 a na4a 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 whexp)if 8c5,(2n jniykure 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 temperatutyp989c/n g1oosd s2sn.1l8jbb *ofbre 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 o fxz/ era w*t; 0*yydlffhdfz+ +9z,p/f length 0.75 m is played when the speed of sound in air is 340 m/s. What is th/;fx ddal + z+fyrt*yzz0e/,phf 9*f we 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:+*fsiz 7 1sed4rkzl o; one is open and the other is closed on one end. If the fundamental frequency of the open pipe is 300 Hz, + ze ;skzros*71lidf4what 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 em/-cnb k3:sqy4k4kl dyit a frequency of 800 Hz in air where the velocity of s 4cds4lk3y-: ybq nk/kound is 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 side by side andjh8n zi6zt ahw::k6xq2uw(4 d 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 litt :8hi6 d6 th4q(2z kaxuw:nzjwle 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. What is the bew-fhg2 . x;lsd6 g 0mxkk7dwp v5ncx6-at 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 frequencys+ )t)ujw(u yf of a musical instrument. If the tuner hears a beat frequency of 2 Hz, what is the frequensywu )+utjf( )cy 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 hornbvm/3c9 fjm394 wnbp qs are 6 m and 7 m respectively. What beat frequency is heard when the horns are sounded on a day when the velocity of soup mw39b4qmb 9 j3nfvc/nd 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 x2qyf6,k2q h p3 cjkj.found to produce a beat frequency of 2 Hz whencp.k2 qfh,kx 2qjyj63 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 sound souribq:(np 8am/wce at twice the speed of sound. qn:b/ wmap8( iThe 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 (norma;.k.ip+ n 6ql5aqb1 qsbs2zkal frequency of 1000 Hz) approaches a stationary observer at one-half the speed of sound. Thekss.6q2 n;1ail+pbkz5qqa b. 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 sp t szs.hcwk5r, -zp1c)eed of 30 m/s away from the source, what is the frequenc5zp.zs,)cwstr 1k -ch y 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 is1ek 85rgezb lg j4ge /k)g mf2x47r6ji traveling at 35 m/s on a day when the speed of sound through air is 340 m/s. The car approa)e7m6 84k/x ge f4be2gg15lki rrjzjgches 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 approaches aa4 pg0a3 g59hai+seg with a speed of 30 4i hpg gaa3+es5a 9a0gm/s. The frequency of the train 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 awu g6op.by* ,lt 120 km/h. The train blows its 400-Hz whistle. Take the speed of sound to6,l.* gboypwu 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 stationary train. -g/c g1o0 +/z(ko7vrdf zgawiThe train blows its 400-Hz whistle. Take the0-ao1wkd(cgv+z/ zfir 7 g go/ 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 awa7yhfaw 44aj;f y from you at 120 km/h. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequh aj;4awffy74 ency 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 p+1g rvoals3;fgxs- - hop;abj,.a 6n hear a tone of 400 Hz. Take the speed of sound to be 341j. a+pfr-g;l a6bgh,ax snsop;3o-v 0 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 the speed of sound inj6(yxfa ;0dxy air is 340 m/s. What is the frequency heard by an observer if the observer is moving away from the trai ; xdjx6yaf0(yn 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 sound in c kgx,d8 w mn79y9dhd1air is 340 m/s. What is the frequency heard by an observer if7dw9dd kc1,gx 89nmhy 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 40va ez028jk u3x-kHz signal is sent out, and a 42-k2v 38xz je0uakHz 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 ssyep*udr 9cf1 ,c: e:o s0)puwupersonic 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 1.4xefyk 3,fg/ i6. What is the half-angle of the conical shock wave foreffk /,y36xi gmed?

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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 th5b4bedp0au1xw we s*8e United States to Europe with a Mach number of 1.05 where the air u 0 w4se8bwx1db5aep*temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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