With density ρ constant, the equation of motion can be written as d d x ( ρ ρ v 2 2 + p ) = 0 by integrating with respect to x v 2 2 + p ρ ρ = C where C is a constant, sometimes referred to as the Bernoulli constant. It is not a universal constant, but rather a constant of a particular fluid system. The deduction is: where the speed is large, pressure is low and vice versa.