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Gas Pressure Acting On Different Objects

  1. Mar 11, 2010 #1
    Does air pressure act the same on all objects?
    Imagine you have two pistons, each with a 100PSI of air acting on one side of them.
    One piston is a cylinder, naturally.
    The other piston is a cone shape.

    Do both pistons have the same amount of force pushing them to the right (see; picture)?
    Or does the cone have less force pushing it to the right because it also has some force pushing it up, down, diaganol etc etc because of the cone shape?


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  2. jcsd
  3. Mar 12, 2010 #2
    Thanks, I think I just needed an analogy to put in to perspective. Cheers.
  4. Mar 12, 2010 #3


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    Pressure acting on an object produces a force that is perpendicular (or "normal") to the surface. Forces are vector quantities, so the force acting on the surface at any point can be broken down into its various components to determine a force in the direction along the axis of the cylinder. You can then integrate the pressure across the entire suface in the direction along the cylinder axis. When you do that, you'll find both pistons have the same total force acting on them in that direction.
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