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Why is there friction?

  1. Jun 19, 2008 #1
    I was just wondering, because on an atomic scale, nothing ever touches due to electron repulsion, why is there friction?
     
  2. jcsd
  3. Jun 19, 2008 #2
    Friction forces occur at larger scale, not that tiny.
     
  4. Jun 19, 2008 #3

    russ_watters

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    Staff: Mentor

    Even when not touching, there are still forces (electromagnetic) between objects. It isn't like every surface is a mag-lev train - surface defects mean the forces aren't perpendicular to the direction of motion.
     
  5. Jun 19, 2008 #4
    Ok I now understand that this the forces aren't perpendicular, but why would this produce heat? Where is the energy being released?
     
  6. Jun 19, 2008 #5

    russ_watters

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    The heat is due to the fact that the interactions are not perfectly elastic.
     
  7. Jun 19, 2008 #6
    Sorry I'm being stupid right now but, what do you mean by that?
     
  8. Jun 19, 2008 #7

    rock.freak667

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    Homework Helper

    a perfectly elastic collision is one in which kinetic energy is conserved.
     
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