Okay, so there's a system with a high pressure tank, connected to a water vessel: The high pressure air tank is (a), and the water tank is (b). The first choke point has the opening area c1, the second c2, and the outflow nozzle has the opening area c3. Let's say the air pressure is pressure p, and the area onto which it distributes force onto the water is Aw. Ve is the velocity at which it flows out the tank. What will this velocity be? I have a vague idea, that give area Aw, I can just calculate how much force is being exerted on the water by pressure p, and apply that much force to area c3. Is that correct? Ve = (p * Aw) / c3 The only problem with that though is that should be describing an acceleration, not a velocity... But to determine a velocity, I need a mass. A mass requires a volume, though, not an area, but all I have is an area (c3). So... How do I find Ve?