• MnemonicBump@lemmy.dbzer0.com
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    27 days ago

    If the water pressure was high enough to spray out, the ball would simply fly off. It’s the perfect equalization of the weight if the ball and the pressure of the water. You can do this yourself at home. Try this:

    Find a marble that fits the opening of your garden hose perfectly. The hold you garden hose upright, place the marble on top (do NOT hold it in place), and begin turning the the valve until you reach the correct pressure. You’ll notice that without enough pressure, nothing happens at all, and with too much pressure, the marble will fly off the top of the hose.

    It’s a balancing act

      • mbp@slrpnk.net
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        27 days ago

        The variables in this equation are:

        • Diameter of marble
        • weight of marble
        • diameter of “hose”
        • water flow/pressure

        Along with some friction outliers, these can be adjusted to find an equilibrium.

      • mic_check_one_two@lemmy.dbzer0.com
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        27 days ago

        Pressure is measured across surface area. The same way buoyancy is measured by water displacement. A larger object has more surface area. 1 PSI of pressure won’t be very much if the object only has 1 square inch of surface. But it would be a lot of pressure if the object has 500 square inches. 30 PSI is enough to keep your car off the ground. A few PSI would be enough to lift a 500lb rock if the surfaces were prepared properly.

      • chuckleslord@lemmy.world
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        27 days ago

        For every weight of ball (within a certain density limit. Won’t work with a black hole, for instance) there’s some pressure and volume of water that will balance the weight and size of the ball perfectly to create a thin layer around the entire surface. Once the ball becomes too dense, there’s no volume/ pressure combo that would do the same (the weight would require too much pressure by volume of water, so it would either stop it or fly full force by while barely levitating the ball). But I don’t think whatever density that would be is found in pressures you could find on earth

      • kaotic@lemmy.world
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        27 days ago

        It’s all about the pressure; more weight needs more pressure but they tune the pressure to match the weight of the ball.