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Powder physics

  1. May 25, 2007 #1
    If I have cube with top side opened with powder in it an i start pushing two sides of cube together will powder fall out of cube the same as with water or other liquid?
  2. jcsd
  3. May 25, 2007 #2
    It depends what kind of powder. If you had a frictionless powder, then it would flow even better than water. If you had chalk powder or something like that, then it would probably form a larger mound and not flow continuously.

    This is only an educated guess, though. I have never tried this experiment!
  4. May 25, 2007 #3


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    Gold Member

    It would also depend to some extent upon how tightly it's packed in the first place, along with how forcefully and quickly you compress the box.
    If it's just poured in loosely, there'll be a lot of air spaces. In that case, slow compression might actually lower the surface level as the material settles into a more compact arrangement. Conversely, a rapid compression could cause the air to blow the stuff out.
    If it's been tamped down so as to leave little air space, a slow compression would probably cause a bulge on top as DH said, but a fast squeeze might 'squirt' it out.
    Why don't you get yourself a plastic box (like Gladware or similar) and some different types of powder. Experiment, already!
    Last edited: May 25, 2007
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