I'm reading my fluids chapter in my University Physics textbook. We actually didn't go over this in my University Physics I course. :uhh: At any rate, I'm looking at the equation of continuity. In explaining it, it says the flow rates through two areas have to be the same because there is no flow in or out. I googled another explanation; it says the masses have to be the same - conservation of mass. This elucidates it a bit better for me. If you choose an arbitrary amount of mass through an area, of course, if there is no exchange of mass with the surroundings the mass will eventually pass through another area. Without doing experimentation, how could you intuitively conclude that the flow rates would have to be the same?