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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 false statec; t/*n9 7wpra3 cgebement?

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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 ep dt6 olch6;h2u q+o,conducted 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 anr wat0 -fwu )9o4ez*i 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 happ z( 75snxy/omcens to the velocity of sound? (Assume that alnyzscx m5(/7 ol 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 ecn.mt,ah2v ms;iy ;en q37p)Hz sound through air )q3ec .2m7 heasv,n y ptnim;;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 /ol nz+emm07o a 400 Hz sound, the wavelength of a 200 Hz sound i/o oe+ nmz0ml7n 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 great7veh 48bpvdu) er 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 leshoi iqel; c;( k0hn-or:rm0j+ s 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 emi7bf mb-u 7oymxi), y,el .wlu)tting waves uniformly in all directions. If you move to a point twice as far away from the source, the frequency of the sound will,wy7,.uuel) ofibb) mx7lym- 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 proportionauy/ zf t+3fs*ppc qo-.l 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. What is p;*ujhrp+ thx9p 1cz*g0xflmm/n:7ythe intensity at a dista *mnl/z*fm9xpp p c0uhhg7j:;+ xrt1ynce 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 from a sound source that is radeg2e.nuq7 yj *ih1:spiating equally in all directions. What happens to the intensity of the sound? 1sgen7eiy2h*pj :.uqIt 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 equally ilha -hh30z gk m.kqg-8n all directions. What happens to the intensity level of the sound? It dza0k3lqh--h mhk8g g .rops 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 beco u9)7z xeo)3p r;sgptfmes 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. What0.4wioc e8yc/vv + eajxsr7mt-t,8c m characteristic of the sound av7+ wx80c cc/ttvi8 mes-,o4m ery.jincreases?

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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 musiccx. ewcbrz2,( al 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"k h-m+re v7hp9h 15liwf1*izj 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 into wyyep 0,8ib29; g(qpppdrqs f9ater

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19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Pressure and displace )ie g625xvll /9xq 0ebihic5ament 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 wave generated by :b-qqs +blk9s- /iiy coz+i7t:vx* oythe guitar as a result of this vibration. What do i9l--o:xvyqysbz k* +it oqcsb+i/7: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 isrku ffb-lbqu; wctz17o5.i ,6. j/zbg 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 j37m f2 v:( bi/xvcxwiin6b m8of length L. What are the wavelengths of the three lowest tones p xi bm :if23jw 8xim7(/6vbvncroduced 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 one o:5; r d(nlhnpjf the following frequencies will not resod(phnln 5:r; jnate 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 freq*+gdv(ir/zfw7 1 bjr. -l jxxjuency. Which statement is corgx+jdrir (f.b-/j*zwjlxv17 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 closed6hl8nevy r(sj2 u2 )3cswxnlv;7 xk,q 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 the three yetmhykm3 +lpxk+sl;w(6w (: lowes( e ;ps( :mwx6 3mw+thklykl+yt 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 in a closed pipe of length L is 200 Hz. 6*ou ekb4j5. fgq -o j/f)fmln Which of the following freqbfofk -/ j6jnlf4g mq5 u.oe)*uencies 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 resoat/yvufb4)1 t bz-y8fnating at its fundamental frequency. Which s f4-t1 yz/f) tvbaby8utatement 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 spg0lyy4 m(6w 2uil7a lceaker produces a tone wiu76wyaci 2(m0 llg 4ylth 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 v hz4 wiyhf4 a,p.g1*wtwo 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 ;2d4qoaxj,cs6tz yn- 6 x*l lbtogether and a particular beat frequency is heard. What happtc 2b nsxoaql6z4 y6d-l,jx;*ens 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 explain 5nrnj4ela g1 6hv2+kls

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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 stationary7 mw9a8mc hes69lfe o ocs2/7f observer. The frequency heard by the observer is7ows m9f62cse ho7ml c/ efa98

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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 obse uv1 x0otaw, am;q0q9urver. The frequency heard by the observa9uq00tu,o ;xw1m qaver 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 o z3ep ;fl(ub-its MACH-speed, its half-angle will decrease by a factor o; ufpe l3(b-zof:

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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/snms l av ;lwhb+: vzz4we6+.:kk)d(wi. What is the air tempera;ww:vsi+nlwdva(em: .k klz z 4)+h b6ture?

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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 th17u 6-dywv r2qot(0r els p)lb3 uzt(le 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 spe+ 7gpd z*tmtpl /+uajsout2(;ed of sound in air is 340 m/s, a bat emits a shriek whose echo reaches it 0.0250 s later. How far ajt+ mzto2dp(u/*;g u+t as 7lpway 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 he4zf0 rwor7m/xc301xe uhs u9gar 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 v48pi32odge 76t d8rlfz+4fg rj nl( hflash of lightning, the distance to the lightning strike is ab g3h ng 74pi2f8(dl4o6dvzfe8l+rjtrout

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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 tsfvd(d,xnti-;qhd ig.( o72s 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.aiw;n 8ow :u8w5 s later. How deep is the well? (Ignore air resistance, and assume the velocitywaw; 8no u8:wi 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 b/zr ) 5 zaks,9earz*ga 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 aid/y a;;yqdzs)j 37 pcur 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 inteoms8tp.c.eji- b- t5 7 xgf,wtnsity $10^{-3} \; W/m^{2}$?

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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-dmvc84g ob94 vf:e.yg(db 6cf hB 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 tap 02hsbem: u8sd)2xohe intensities of two sounds with intensity levels of 70 dB and 40 edh 8uxa0m)s2p os2:bdB?

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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 3oe d1h8 (ndzagarage is 100 dB. What is the intensity level genero8 ae (1d3zhndated 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 of 6.0 zah -+p6ca/dc m from a source that is radiating equally in all directionsa+6c /cadzh p- 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 that is radiating rig7x g 5l ,w fyd+*an5bmgh:6equally in ndlagy5:g fh7x m*6i,wr 5+bg all 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 be uniformly dx kb .5 idvag8jd+2lj:istributed in all directions. What is the inten:vkjj ldg+ di .a52bx8sity 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 5.7p)3fqh z8d/ke zh pz,00 m from a barking dog. What would be ppzhdz,8h3kfz)e7q / 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 gctm8tlulir x vzqphf*2ts+3 0 ,;r;+from a sound source the intensity level is 60 dB. What is the intensity level (in dB) at a point 2.0 m from the source? Assume that the source radiates equally in t2fm*glz;+sr0i;3+upv 8 t,rhtx qclall 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 ( ot 4kyn3ls8qa point source is 95 dB. At what distance will it be 75 dByot(4n k3ls8 q?

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The third harmonic o a1t7ld;skm*jf a complex tone has a frequency of 1200 Hz. What is the frequency of the f;a7 tj1 *lsdmkourth 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 2s 8sb5kje4nmmo3.gnzjxt 3(length of the pi8jn3o m (3ns.x4b ej5s mgzkt2pe?

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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 Hu6to-swc s*dk):6e6)ery 4p2o1nicr9 wjdv m z. What is the frequency of t)ekt ocd 6c2 pwr-n6*)r odi:js61wyume sv49he lowest tone that 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(kikjom.3 y9b/ j 8bjp a length of 0.80 m. If the velocity of sound in air is 340 m/s, what is the frequency of the second harjmki(/j3op jb9 y kb8.monic?

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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 tem+1io0nvvgbd s6)cp7 f; eqq+qperature 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 inl v9u *jb.sr4bh7po37eqk2x 2d )p40wpl huee a pipe closed at one end is 330 Hz. What is the frequency of thu32p2u*9h bedp jh o0le4ve plrk4)q77s.bwx e 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 c 0shezfa87r-on one end that will have a fundamental frequency of 60 Hz on a day when the velocc08a f h-ze7srity 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 zt az4:pzqxel+76:vr a room where 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 il5 twa (.ehz.es 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 sound ins9lg0hp 12j.wp ckst- air is 340 m/s. What s92.-hl s 0kpjtwc1pg 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 tj) 1vh(ox4ci closed on one end. If the fundamental frequency of the open pipe is 300 Hz, what is the fundamental f v1)(xoihcj4trequency 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 thac* )y5(tivmra 8o2m me velocity of sound is 340 m/s. How much farther back would source 1 have to be moved r* o2y5miva8a)mt( cmso 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 drivetqqvv;*u8qox(2z k hk . v,9sin by the same frequency 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 possible the distance from the person to the other speaker? (The sound speed is iuxtqk*s.vq98,; ho(v zqkv2 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. :1qt1jfiko/x 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 (-wt (qu xn( fr8/v ddyvrw;h3550-Hz tuning fork to tune the frequency of a musical instrument. If the tuner hears a beat frequency of 2 Hz, what is the frequency of thexuwdq-(wr tvyfd3v/h8;( n( r 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 soun8 c31t5bh kp:y qiam0ulg7dm*ds produced by two horns are 6 m and 7 m respectively. What beat frequency is hb7 d*tpl35:u gicmma0hyk8 q1eard 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 vioqrd7p .f*luz ,ywxb736pg -imlins in an orchestra are found to produce a bea7fquw.6*y m rdgpx,lb7z3- pi t frequency of 2 Hz when 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 souns qm,hqh5 :g4r i//.3qvvpj tld source at twice the speed of sound. The obqv,5/ /j. q4glvm:tqihh3 ps rserver 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 frequen ayxid((u4;o qcy of 1000 Hz) approaches a stationary observer at one-half the speed of sound. The observer hears a freq(u(aioyq 4xd ;uency 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 speedwu(v7m0 -abg s of 30 m/s away from the souraw70sgvbm -(u ce, what 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 35 m/s omwr(ei)cpp -o(vj ( 3gn a day when the speed of sound through air is 340 m/s. The car approaches and pa(gwp((-)evc ro 3mpji sses 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 approaches9.gzg eqv8cl5wk o k1q7d4y -lz f.f6p with a speed of 30 m/s. The frequency of the train horn is 600 Hz and the speed of sound -od.g49eq kwk f1ylz68. f7 pqg5vlczis 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/h. The train blows its 400-Hz wh28lao: 1jgx3ew ni ;3z(fig dpistle. Take the speed of souewi2j gz3fp1d:; niga(l8o 3 xnd 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 stationdmdp8p-v dfb),vh2h6 ary train. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequencv h8h, dd 2m-ppfdb6)vy 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. z;.1rt)a qw wnfmi/ym;7ohe52w lj5 mThe train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency do you.q5y 2z wj hronmam5m;w;1wf il/ te)7 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 kmj7ankp9g q4bkxa6++ah s ;jwybi8 /l 9/h. It blows its whistle, and you hear a tone of 400 Hz. Take the speed of sound to be 340 mj/b kw6xyj ;a9n4sk8l bhi+a 9qa+7 gp/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 jdv2zq24k 4 + :kkljkzis 500 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by an observer if the obsez :+lk4qdkv 2zjjk4 2krver 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 500 Hz. Assume thd a.f, c8 5n6e cdhgmc2t+r /yv+w:dkux4v2k le speed of sound in air is 340 m/s.g5yntx6hdkc,+ e 2f:c2 u/+8.mkvwa 4 dl vcdr What is the frequency heard 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 theqk ,wtdsuisoa,d5,e /9c +wh: speed of an object. A 40-kHz signal is sent out, and a 42-kHz signal iws,s ioeq,tc9 , wh/ak:d5+uds 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 supersonic airr9j5 d pvbh.0fcraft 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, suwai+fb )x2 is the half-angle of the conical shock wave formafxu2 i)s+b ,wed?

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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 Statq2chfp o/h 34lsx,hnit, q75tes to Europe with a Mach number of 1.05 where the 3p4 h/h,c2f7qqotn,its5l xhair temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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