sound wave

2003

2007-03-27 3:05 am

http://img137.imageshack.us/img137/231/phy1kc1.jpg
(the wave is bends away from the normal)

A sound pulse travels from medium A to medium B as shown.Which of the following deductions is /are correct?

(1) Sound travels faster in medium B than in median A
(2) media A and B can possibly be air water respective.
(3) When a sound wave travels from medium A to medium B,its wavelength will increase.

I think all statements are correct,but there is this choice.Which is/are wrong?

回答 (1)

backright

2007-03-27 3:59 am

✔ 最佳答案

I don't know whether there is an exceptional case.
(1) should be correct, becasue left-hand side arrive at B first, as the distance of left-hand side travelled after this moment is longer than that of right-hand side. velocity in B must be faster.
(3) according to equation, as frequency cannot be changed, wavelength will increase as speed increases
(2) That should be true for normal situation. The interaction of particles in water is stronger than that in air, so sound travels faster in water. In (2), it states that "can possibly". No matter there is an exceptional case (temperature, state of water, ....), it "can possibly".

But if you say that there is something can be wrong, is the angle bended away larger than/ smaller than calcualated result?

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