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B When does gravity take over surface tension?

  1. Sep 19, 2017 #1
    I want to demonstrate to flat earthers that water does indeed stick to a ball. If we want to do a scale model of the earth, at which radius will gravity overcome the surface tension?
     
  2. jcsd
  3. Sep 20, 2017 #2

    CWatters

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    That would be a waste of time.
     
  4. Sep 20, 2017 #3

    CWatters

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    Put a drinking straw into a glass of water and the water will rise up the straw until gravity "overcomes" surface tension.
     
  5. Sep 20, 2017 #4

    Andy Resnick

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    The Bond number (Eotvos number) is the ratio of gravitational and interfacial energies: when the Bond number is high, gravity dominates and vice-versa. So all you need to do is write down the Bond number for your scale model and determine what the critical value of 'planetary' mass is (when Bo = 1)
     
  6. Sep 20, 2017 #5
    For FEers, maybe. The question itself is worth an answer, as it is an interesting physics challenge and I would like to know the answer.
     
    Last edited by a moderator: Sep 20, 2017
  7. Sep 20, 2017 #6
    That's a good start! I'll check that. Thanks!
     
  8. Sep 20, 2017 #7
    Is there a formula that I can use?
     
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