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A Freezing question

  1. Jan 15, 2006 #1

    Its the holidays and i was just thinking if you have a jar with some water in it and you put it in a freezer say 0 degrees and the jar is constantly being shaken rapidly would the water freeze up over time? or simply if a body of water is moving does the freezing point decrease in proportion of how fast the water is moving?

  2. jcsd
  3. Jan 16, 2006 #2
    as I see it , when you shake the jar you increase the water`s temperature.
    for the second part of the question,by moving the jer at a constant speed the system is undisterbed(no extra forces) and thus the water will freeze.
  4. Jan 17, 2006 #3
    Belick, I have a doubt, does Drag force in fluids act inbetween the particles of same fluid. In that case the body is moving with uniform speed nullifying the Drag force.
  5. Jan 17, 2006 #4


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    Depending on how vigorously you shake it (and considering other turbulence factors, such as the shape of the jar and amount of water in the jar vs. empty), you would increase the temperature a little bit. I'm not sure how much, or whether it would be a significant amount.

    What would more likely happen is that the water would freeze in about the same length of time (or a little longer) as an undistrurbed setup.

    But, it would freeze differently. The water would start turning to slush rather than ice, like in a tray. It would appear to stay liquid longer, but that's really because you are forcing all the water to cool before any of it solidifies. (That's how you make ice cream).

    The shaken jar would ultimately be frozen about the same time as an undisturbed jar but it would be hard to verify this, as it would be difficult to pin down exactly when all the water is frozen in each sample.
  6. Mar 3, 2008 #5
    Wierd Frozen Bottle

    Recently it was cold as all get out here (Chicago). I think it was around -10F. What happened to me was that I left a bottle of Aquafina in the car. I went and got in the car and noticed the bottle. I noticed it was still liquid. I touched the bottle and it froze over the course of a 2 to 3 seconds starting from the point where I touched it. Anyone know what this is called. I vaguely remember hearing about this in the past but can't remember what I'm looking for. I searched for freezing water and shock and came up with this thread.
  7. Mar 3, 2008 #6


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  8. Mar 3, 2008 #7
    Would this not be a simple equation? Each time you "shake" the jar, you add a certain amount of kinetic energy (k). If k < avg (k2) of freezer then the water will freeze. If k is larger than k2 you will end up thawing your freezer instead.

    Disclaimer: I'm no physicist.

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