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Equation help

  1. Feb 18, 2004 #1
    Is anybody aware of an equation that can be used to describe a floating ball in an air jet?

    http://www.ap.stmarys.ca/demos/content/fluids/bernoulli_floating_ball/bernoulli_floating_ball.html [Broken]

    I'd just like to put numbers into an equation and prove that the forces on either side of the ball are equal.

    the balls mass is 2g
    take gravity as 9.81ms ?

    F=ma (0.002kg x 9.81) = 0.0196N

    that should be the component of force acting downwards upon the ball, would you agree?

    Now i'd like to find a way of calculating the force acting up on the ball, which I'd expect to be close to the figure above. Any suggestions ?

    I dunno if i'm on the right track because i'm a bit thick but should I be looking into the drag coefficient equation ?
    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. Feb 18, 2004 #2


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    I do not think that you will find a single simple equation which will do what you want. One could create a mathematical model of this situation, but I cannot guarantee that the resulting system of equations would have a closed form solution.
  4. Feb 19, 2004 #3
    i'm probably just better off saying that it follows newtons 2nd law. Thnx for reply anyway :)
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