Fluid Mechanics in Physics

A fluid pushes in every direction at once, which is why pressure and not force is the natural quantity to work with. It rises steadily with depth, and it rises for a reason that is easy to miss. A deeper parcel of water must carry the weight of everything above it, so the pressure at the bottom of a tank is the same whatever shape the tank is, and only the depth matters. The same idea gives the buoyant force and the reason a steel ship floats. Once the fluid moves, speed and pressure start trading places, and the blocks end with the relation that governs that exchange and the two classic results that come out of it.