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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 false statement?o elvzaxjan8g4 1a(3 2

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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 faste+-j tcv s:- liujlg1)fst 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 j uogg/6,1t-fn6 qoh do+ 3tbwrod?

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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 th. p )yn2y5t7a)mgnpuw e air increases, what happens to the velocity of sound? (Assume th nty27ag5py wn .))pmuat 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 th(y p)vh0hhl8 erough vhh8( h)lyp0 eair 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, the wavelength of a 200 a8xz8h/gx+o+pzss )nx (,vj mHz sound in air iszxsxom,+ an/hv ( jsg +8pz8x)

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sound vibrations with fr(znx9mng 91zedzb09xo f o+z*equencies 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 thafe fhc4 v.ywim 4;,6jrn 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 il)5qsac*tggg ,2 o.j is emitting waves uniformly in all directions. If you move to a point twice )*i.gag q,ojg 2clt5sas far away 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 is propor sfop 1lcn-a;n85eq(utional 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 dee pxvv5wo/e fmwi:*sb 4h0 /1 from the source is I. What is the intensity at a distancme vvbx*eowh /wep450:/fi1se 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 sourc 9ghn3y1 1lo3espr bj2e that is radiating equally in all directions. What happens to the intensity of thenlb 29h1geo y3 jrs1p3 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 +/(-ma- pd di3e xbj7vktcewk//dd s2source that is radiating equally in all directions. What happens tpv/e7wa+e kdcdkjx /-m-s3i d(/bt2 do 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 increasesxwxh0wd:7y f(vp.k)9yx /bw2 x w1yk x 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 sbii i2 f/d *v2cbu8+gqv-ybq.peaker emitting a pure tone. What characteristic of the soug ivc+ 2i*8dubyifbb2/q vq-.nd 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" ox kpr:8d p sgj;tlb.(xx;0mi;bi a(9 wf 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 nog1v.+xi bii(amp/:s:pvp 9oj te?

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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 z l4jo-d .usl.air 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 displacqn d5mo(o ptp )3-h5ulement 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 b2 zkb l5-n5nldy the guitar as a result of this vibration. What do these two5lkln5nz 2b-d 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 /rtd1plw- f23jvc fz( 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 t0s4so im/d o621dktnfhree lowest tones produced by this piped nsoitd0 16fk/m24o s?

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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 h,k9mi*qp/l*a(ne:k b *sujr L is 200 Hz. Which one of tk9*qe :*i, (p u/abrnmkhs*l jhe following frequencies 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 frequency. Which 6-m+wjqi:yv v2 )zdc 90tfhxrstateme+vr9 t wq hjd0iyf)z-:x2m6v cnt 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 s5u+.z d zui,athe 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 wavelengzs hw56 89x 6tjkz.etoths of the three lowest tones produced by this pipe?z9 8z xs66ehj tko5t.w

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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 pipdl( 7b0v ne8zt(l3jx pe of length L is 200 Hz. Which of the d(0v8 3eplxl( 7zn jbtfollowing frequencies 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 fundamentalfx *,8uol3duq frequency. Which statemenfluxq, 3u8o* dt 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 ppi. . 9ke*tljsame source. Each speaker produces a tone with a* jl9pkt.p.ei 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 two sk4mhsle5tqes 8*:m8 tound 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 pag1n c8q w71(bhs7ues zxhj2s xcn;1f;rticular beat frequency is heard. What ha7sjfc;xs 1 cwzs (en g1 8qnb2hu7hx1;ppens 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 explywqapj0n/q k,g o .+(m+k- ahzi ma1f;ains

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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 obseuc : n-b84r1giqvktkd 6 y0tg.rver. The frequency heard by the observek04gdt ucgy n-b:r6v.qik81tr 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 frequency5 xnf -ec*buy: heard by the obs:cxf b*n -ey5uerver 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 by a b+(e2, vp b,ygswa yl5factol2w5e gay pv yb+b,,(sr 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) j,zftt9phowdhd,14x9dkjj: f v;vtr u 6c+8 m/s. What is the air temperature?tjz, ; kfhhdv6 v trwjf) 48u+,x9otpc9dd1: j

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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 3-d 7,fdtn: ).oshymdw ft:hpof 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,deq3gr3pn4r1v cl )owq(i8t9pri /x 8 a bat emits a shriek whose echo reaches it 0.0250 s later. How far away wqi qnr tc9(4dw l ri1prgx/ov3)e38 p8as 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 temperaturelyc72e--u sxw+*g nmg 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 distance m.ismj;uec-/3gz 3ta to the lightning strikez;mi3tjsu m e-acg3/. 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 sz (c81 uypyf;xr lb73o 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 d 9 yz+/ok,6wcl:i8b kizfk314ozitdlater. How deep is the well? (Ign9i+o kifz3c d/k wz1lk8tyoz4: ,6idb ore 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 souy;2f y.z-v l;t bf)mm3ft x8kmnd 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 ai5x-1kym q *-wa qetuq9r 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 intens75imrsh/. e;9kq h l*hsorp)aity $10^{-3} \; W/m^{2}$?

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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-dB sound?7z-sht6 :d s bv5hkk.c

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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 in8.ztit1gwg43 /nnafw bu/ )fotensity levels of 70 dB t/.iuo 1/3gnff 4ztgawbn w)8 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 engines in a garage is 100 dB. What is the inteah7fo1qdiv ep) (;+ mensity level generated by one eoh ipevme7q a(f+d 1;)ngine?

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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 sb4+bm,* vffre eawa.97o r,bv ource that is radiating equally in all diro,,re7 bv a+r me*f4ba9vb.wf ections 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 frobj8 t5k 5k8 -etu4hikdm a source that is radiating equally in all directions i 8u4 b-ket8 5kjitk5hds
$6.0 \times 10^{-10} \; W/m^{2}$. 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 qh mg/p+ )a 2m:a)nxgwis assumed to be uniformly distrib)pg xwhan) /+:m2mgqa uted in 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 dB at a dista t-cz *v(jf)romk:8si )jalr8nce 5.00 m from a barking dog. What would be the intkcv:o j)l r *i8)trsazf(j -8mensity 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 sounjuocp: uy(h+ 4d 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 radc+ uju y4(op:hiates 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 51thw:r ;q f4f)cz cs89kv dxm5.0 m from a point source is 95 dB. At what distance will it be 7q tsxf)zc:9 8df4r;cmw1vkh5 5 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 freque/qy i5pj9fgm.+g+ knzncy of 1200 Hz. What is the frequency of gf g+jz/.k+5pq ni9ym the fourth 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 +;in f*lpb lotd;i,0tis the lengtf+dl t;no,i;b0it pl*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. What is the94me+u3; nsk xu;s2uz fyidv0 frequency of the lowest tone that will resonate in an open pipe of luk ;m xue;iu+zs 3 2fsv4nd0y9ength 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 lengt ml+ydj,l )6ycq,./huq 7narnh of 0.80 m. If the velocity of sound in air is 340 m/s, what is the frequency of the second harmon+ay6yq7/l,qh,djn c.r lm u n)ic?

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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 wherrh+ + /ej*xao9p1wvsy e 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 one end is 330 H4zu,*rc7 i*1 q*rsel6tm zbsu4 og v+oz. What is the fr*l*,z rb4 vg+z ssu6q *uc oro17ei4mtequency 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 on*ss1 g fljsz((4gvp1 qm. 4zioe end that will have a fundamental frequency of 60 Hz on a day when the velo4 s1m*( zfv(4pzj1qis .golgscity 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 inaw w cdxgd)9nd-a-0a1 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 is in a room where the temperatud5:0)iugig i ire 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 in air i 8v: xp4pwugp/h3(f nps 340 m/s. What is the fp( ngxphpv4p3 /:w8uf undamental 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 ob*0 m:crm8pv+ l-uct/ )x av7t,tavcef the same length: one is open and the other is closed on one end. If the fundamen*l0v u/tmtvbr tcc,ea)p7ax-:v+ cm 8 tal frequency of the open pipe 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 emit7wwap ate**i8;efl q: a frequency of 800 Hz in air where the velocity of sound is 340 m/s. How much farther back would source 1 have to be moved so an observer in front oap*i8et la*; w7f weq:f 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 sampe / 5fqye 8v77s 1zai(mnetv8e frequency of 500 Hz. If the da18 evnp q7 s(zevm/78teify5istance 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. xvdz jgbo..*pss vs a jib9-nf*:v883 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 to tune the frequency of a musicg dc1qg37wix (al instrument.qwgicx 713(gd If the tuner hears a beat frequency 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 sghs7e dyzppa68 0po+)ounds produced by two horns are 6 m and 7 m respectively. What beat frequency is heard when the horns are p 8+7y0doh)6 pszeagpsounded 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 4rxvjldoys 3.hkj18bym+ +/a on two violins in an orchestra are found to produce a beat frequency of 2 Hz when a frequency of 660 Hz is played. What percentage change in tla +3s+ymhvx r j4od81.yb/kj he 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 ai lh*:yi i/o1of sound. The obylo1/i:i h*aiserver 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+ *d+agwr+h jn4gr5ss of 1000 Hz) approaches a stationary observer at one-adn 5srw j +hg4gr*+s+half the speed of sound. The 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 mo2v2yxdc7fiv s +tfk()ves 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. vsf7vcd2+) (fkx2yti )

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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 on a day when the ;f. v xb:amjm*yey+p- speed of sound through air is 340 m/s. The car approaches and passes an observer who is stan+p* e.ym ;-ba:vmjfyxding 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 5 ss3*h5ootad*l m ez23 kul8oobserver when a train approaches with a speed of 30 m/s. The frequency of the train horn is 600 Hz a35o5l* ha tlos*e23 uzdsm8k ond 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 120 km/h. The train blows it , /.q2dsyy9f qdvidq;s 400-Hz whistle. Take the yq 9;vsi q.q,2/f dyddspeed 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 toward a stationary q2xnk*kf m;z--j )euk pf9j l1train. The train blows its 400-Hz whistle. Take the speed of sound jkf u;k lfmn) x-k9jqe1z p2*-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 trai:fncdy x 90,otanr+p. n blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency do you hear9daf+ nc0:n,xp tyro .?

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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 atiopfd uczkm(djk8+ r7 h fyl6q),(:0s 120 km/h. It blows its whistle, and you hear a tone of 400 Hz. Take the speed of sound to be 340 m/s. Whaky kcu, d +d0rpzq(l if7 8o6(:)sjhfmt 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 tq . w)w5jmeakbh(4/ :b;c ku9ssf dss:he speed of sound in air is 340 m/s. What is the frequency heard by an observer if the observer is moving away from the trainaes;4 k)u5::9s wq/s (dfmhb.jk wcbs 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 hzrfth)(8j) s0 fner**4ij:wde0mreo orn is 500 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by an observer if the odoj*e()*4t) rr:inzr 08m0 ffw hjes ebserver 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 is sent ob;x frx/(z0 ,ps)2cuqbn:ofa, o)ye fut, and a 42-kHz signal is returned. Assume the speed of sound is 345 m/uxa r,,x;) (y fo2pbfsqno0c ebf:/)zs. 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 pyy/- *ks)sgx q6kyb9.zz9lx 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 Mam(w zg)kxf 88och 1.4. What is the half-angle of the conical shock wave zgkm8w 8of)x (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 flies from the United Statessp e/mru: m3d(*(z tth to Europe with a Mach number of 1tdmh*r 3:t/ z(smuep( .05 where the air temperature is $5.0 \; ^{\circ}C$. What is the speed of the plane?

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