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Vibrations of a particle in solid

  1. Jan 30, 2012 #1
    I know that particles in a solid are not fixed. They are constantly vibrating about their mean position. That is because of their kinetic energy.

    I was imagining a situation,

    lets say solid moves towards left of it's mean position. then the inter-molecular forces of attraction on the left side become slightly larger than that present on the right. But I also have to consider the repulsion between the electron clouds and the nucleus. But, obviously the forces acting are not in equilibrium, that is why the solid particles are moving around.

    So, what exactly is happening. how are the forces able to compensate?

    The vibration that is happening, are those SHM. Then the forces will be able to change depending upon the mean position.
  2. jcsd
  3. Jan 30, 2012 #2


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    Your question seems to contain the answer, actually. Take a mass on a spring and start it bouncing - that's SHM. Connect a whole chain together. They will all bounce up and down at different rates but the mean length of the chain will remain what it was when there was no bouncing. Now imagine it in three dimensions - the same thing applies. The forces 'compensate' because the (mean) shape it takes up has the lowest potential.
  4. Jan 30, 2012 #3
    Not to mention that all matter may be vibrating through out 11 dimenisons at the quantum level according to String Theory.
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