Because most civilizations use submerged surfaces such as dams to control flooding and manage their water resources, engineers must understand pressure changes and design their equipment to perform under extreme situations.
When you dive into the deep end of a swimming pool, you can feel the pressure pushing all around, and the deeper you swim (or sink, if you're not a strong swimmer), the stronger the pressure you feel. At large depths (such as the bottom of the ocean), these fluid pressures can be downright deadly, which is why professional deep-sea divers must use specialized equipment to survive.
In this chapter, I show you some of the basic calculations that you can perform on a submerged surface. I explain the types of forces that are created by fluid pressures and how to calculate their quantities. I also show you how to apply fluid pressures to your free-body diagrams (F.B.D.s). Finally, I explain how to calculate partial fluid pressures on gates and openings.
For the purposes of this text, I deal only with incompressible fluids (or fluids that don't change volume) such as water. The study of incompressible fluids and their pressures can be broken into two categories: dynamic fluids and static ...