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Collision Questions

  1. Feb 19, 2008 #1
    When a stone drops on a surface.....the vibration on the surface....does it continue to spread forever....but keeps becoming more and more negligable.....does it travel distances forever or does it slows down at some rate that it forms an asymptote?

    Thank you.
    Last edited by a moderator: Feb 19, 2008
  2. jcsd
  3. Feb 19, 2008 #2
    I suppose ideally the wave would propagate forever but vibrational waves are quantized. If the intensity of the wave is low enough you could be waiting a very long time to detect a wave and may have trouble distinguishing what you are trying to detect from the surrounding thermal vibrations.
  4. Feb 20, 2008 #3

    Andy Resnick

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    The wave represents a coherent excitation; dissipation (friction, viscosity, etc) will pull energy out of the wave over time. At some point the energy in the wave is comparable to thermal energy, and the wave cannot reasonably be said to exist.
  5. Feb 20, 2008 #4
    I guess technically...you are right....you are right to such a extent that even if the vibration does manage to travel beyond some point...a slightest explosion can reverse its direction...but the point I was trying to make is that....even though...the direction might be keep switching...does a point ever really come where theoretically, the wave Perfectly(100%ly) disappears?(I know that it will transform....but will it ever stop travelling?)

    What exactly is vibration anyways? What is a wave? looking up in wikipedia didn't help so I am looking for something different....
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