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Doppler Effect

  1. Jan 15, 2012 #1
    When a source emitting a sound of a specific frequency moves towards the face of a cliff at a speed. The frequency of the sound that reaches the cliff is for sure not the same as the frequency emitted from the source due to doppler effect.
    Will the frequency of the sound reflected by the cliff return to its original value(without doppler effect) or will it remain the same as the frequency that reached the cliff?
  2. jcsd
  3. Jan 15, 2012 #2
    I would say that the frequency of the sound simply remains the same.

    Think about it.

    Sound is a high/low pressure wave traveling in air and frequency is the distance (in time) between two consecutive high pressure peaks or low pressure valleys...whatever...the thing is once this pressure wave has been launched and put in motion in the air by the source...the source becomes irrelevant...the wave is now decouple from the source.

    Additionally, we could say that the air does not know anything about the "original" frequency of the sound as it came out of its source...the air just ends up "seeing" the resulting frequency of the sound, resulting from the "original" frequency of the sound, "plus" the effect of the traveling velocity of the source...

    does this help?
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