In an experiment to study the interference of sound, two loudspeakers S1 and S2 give sound of a certain frequency. When a microphone is placed at P where S1P = 3.4 and S2P = 4.2, a loud sound is detected. Which of the following is not a possible wavelength of the sound?
A)0.2 B) 0.4 C)0.6 D) 0.8
我知道ANS.係C = =但係唔知點解,,,有無人可以計一計俾我睇
拜托曬
簡易PHY (WAVE)
2008-11-24 3:31 am
回答 (2)
2008-11-24 4:07 am
✔ 最佳答案
Path different= 4.2 -3.4=0.8a loud sound is detected means a constructive interference occurs.
如果Path different/wavelength=0,1,2,3等整數,constructive interference先會出現
由於0.8/0.2=4, 0.8/0.4=2, 0.8/0.8=1 但0.8/0.6=1.3333333不是整數,所以wavelength無可能是0.6 , 而答案就是c
2008-11-24 3:54 am
paht different=4.2-3.4=0.6
0.6=(n+1)入
for n=0,入=0.6,
for n=1,入=0.3,
for n=2,入=0.2,
for n=3,入=0.15
Ans(a,b,c)are correct,but D is not.
Therefore,the ans is D.
But your ans is C,you must check for the ture ans firstly.
Maybe the ans is wrong,you may ask your teacher.
0.6=(n+1)入
for n=0,入=0.6,
for n=1,入=0.3,
for n=2,入=0.2,
for n=3,入=0.15
Ans(a,b,c)are correct,but D is not.
Therefore,the ans is D.
But your ans is C,you must check for the ture ans firstly.
Maybe the ans is wrong,you may ask your teacher.
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