Fluid flow through a constricted pipe — pressure drops where velocity rises
Pressure: High → LowVelocity: Low → High
Bernoulli's equation (1738): P + ½ρv² + ρgh = constant along a streamline. Where a pipe narrows, fluid must speed up (continuity: A₁v₁ = A₂v₂ for incompressible flow), and by energy conservation the static pressure drops. This explains how airplane wings generate lift (faster flow over curved upper surface), how carburetors work, and the Venturi effect used in flow meters. The colored pressure gauge cylinders show manometric pressure — they rise where fluid is slow, fall where fast.