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Video about pressure in kinetic theory

  1. Oct 2, 2016 #1
    Hi,
    I am looking for a video helping intuition on pressure, in the context of kinetic theory of gases.

    I remember seeing a video where someone poured a bucketful of little hard balls (lead sinkers for fishing?) onto an electronic scales (a dynamometer, really) showing that this corresponds to an average weight force on the scales dish, and hence to a pressure (most of the balls did not stay on the dish, but bounced away).

    This was a lot of time ago... I think I have seen this videe I'm talking about on a tv program or perhaps during a physics class back when I was in high school. There was no internet at the time.

    I tried looking for something like that in the internet, but the only similar thing I have found so far is this video on youtube (golf ball atmosphere);
    It's not exactly the same thing, though, and what's happening is not very clear to me.
    Do the balls move because of a flow of air, or because they're hit by the fan blades?
    Does the partition lift because of the average momentum from collisions with the balls or because someone is pulling the thread it is attached to?

    Can anybody point me to an intuitive "practical" video, like the one I'm referring to?

    Also, related to this, I am looking for an interactive applet about kinetic theory, possibly in flash (java is becoming a pain, because I have no control on the software in the computers I'm using, and the IT people take ages to change things).

    Thanks a lot

    Francesco
     
  2. jcsd
  3. Oct 5, 2016 #2

    Bystander

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  4. Oct 6, 2016 #3
    Hi Bystander

    thanks for your reply. I have found several nice applets on kinetic theory, and they sure help intuition.
    I had not found the one you're suggesting, and I think I am going to use that too. However, it is a bit too advanced, since it involves the concept of entropy.

    I was thinking of a simple "practical" demonstration using macroscopic objects, like lead beads as molecules and a kitchen scales as a manometer.
    That's what was used in a video I saw ages ago. I assumed that rhis is a standard demonstration in American physics classes (I am not from the USA), and that I would easily find a video . Apparently it is not...

    Applets on kinetic theory I have found


    Thanks again
    -Franz
     
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