CE 2200 Chapter : Chapter 3
Document Summary
Pressure: a normal force exerted by a fluid per unit area. Absolute pressure: the actual pressure at a given position. It is measured relative to absolute vacuum (i. e. , absolute zero pressure). Gage pressure: the difference between the absolute pressure and the local atmospheric pressure. Most pressure-measuring devices are calibrated to read zero in the atmosphere, and so they indicate gage pressure. Pressure is the compressive force per unit area but it is not a vector. Pressure at any point in a fluid is the same in all directions. Pressure has magnitude but not a specific direction, and thus it is a scalar quantity. Throughout this text, the pressure p will denote absolute pressure unless specified otherwise. The pressure of a fluid at rest increases with depth (as a result of added weight). Free-body diagram of a rectangular fluid element in equilibrium. When the variation of density with elevation is known.
