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Archimedes principle free fall problem

  1. Mar 23, 2007 #1
    I have 2 question about the Archimedes principle?
    1. does it hold in a vessel in a free fall? why?
    2. if we imppressed 2 same hollow bodies in water, and just one of them has a hole at the bottom. which one is more difficult and why?

    thank you!
  2. jcsd
  3. Mar 23, 2007 #2
    I assume you're talkng about buoyancy. Re question 1) I would say no, first off a fluid becomes a somewhat different creature in free fall. without external confinement, the forces keeping it in one place are unlikely to provide enough cohesion--I would think of it sort of like a pool of mercury. Without weight of either fluid or object, it sort of lacks meaning.

    for 2) what do you think? Imagine a golf ball sized whiffle ball vs a pingpong ball. Remember archimedes said buoyancy forces are proportional to the volume displaced.
  4. Mar 23, 2007 #3


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    Buoyancy depends on gravity so it won't operate in free-fall. If you had a globule of water in zero-G and gently placed something inside it, the object would stay still except for currents. You can't have 'floating' if there's no up or down.

    I don't know what you mean by 'difficult'.
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