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What is the Lubrication effect

  1. Aug 4, 2011 #1
    When you have a bed of balls and you tilt the plane on whichh these bals are located, sometimes you dont get them all moving like a bed as you expect. Sometimes some balls pop. Is this call the lubrication effect? is it due to some local pressure spike focusing on solely 1 ball? thank you very much
     
  2. jcsd
  3. Aug 4, 2011 #2
    It's called "stickiness".
     
  4. Aug 4, 2011 #3
    stickiness? sorry I dont get. If the balls are moving like a bed (they rotate), and suddenly one pops (only happens when the plane below them is moving), is this stickiness?
     
  5. Aug 4, 2011 #4
    Thank you very much for your reply Naty1, but still I dont get it.
     
  6. Aug 4, 2011 #5
    I suppose that Naty1 was kidding, I never heard of lubricant effect, so I can be wrong but I believe that you are not using some absolutely flat surface and that the balls hit each other all the time. Since all balls are moving and having some movement in it's axis when one ball pass in one little surface imperfection it jumps a little, when it comes in contact with the others balls the rotational movement of the others balls hit that one and kick it up.
     
  7. Aug 4, 2011 #6
    If there is a some friction between balls, when a trailing ball rolls into a leading ball, the mutual rotation of both balls, plus the ball against ball friction causes the trailing ball to rapidly climb, almost straight up.

    I'm familiar with this phenomenon from open wheel racing when I was young and daring, only the tire to tire friction is on the order of 1. When tire touched tire, the trailing car jumped into the air. I think the same mechanism is happening with these rolling balls.

    This has nothing to do with lubrication.
     
    Last edited: Aug 4, 2011
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