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Relation between light and sound speed

  1. Sep 30, 2005 #1
    Hello everyone,
    I was wondering if there is any relation between the light and the sound speed in a liquid. For example, light speed/sound speed = constant, or something like that...
  2. jcsd
  3. Sep 30, 2005 #2
    Not to my knowledge. The mechanisms of EM and mechanical wave propagation aren't the same.
  4. Sep 30, 2005 #3
    Thanks for the answer, but i think that there might be some relation.
    The thing is, I've got a problem in which I have to use light to measure the speed of sound in liquids.
    Measuring the speed of light wouldn't be a problem, so I thought that there was some mathematical relation between them. This would allow me get to the speed of sound using light. Maybe my idea is wrong, but I've got no other ideas. Do you suggest something?
    Thanks a lot,
  5. Sep 30, 2005 #4
    Maybe a piezo crystal, signal source and an oscilloscope. You can use the piezo crystal to send an ultra sound pulse to the liquid and detect it with the same crystal as it returns from the other end of the container. Using the first and second reflected signals you detect on the scope you can measure the time the signal took to travel through the liquid pretty accurately. I did a lab like this with solids and it worked like a charm and it should work just as well with liquids.
  6. Sep 30, 2005 #5
    Could you explain to me a bit better? I'm still at High School, so I don't have the knowledge I wish I had in Physics. What are piezo crystals and oscilloscopes? What do they do/measure? Something else, correct me if I'm wrong, but in your proposal, I wouldn't use light. But I have to use it.
    Hope you (and others) can help me,
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