8.2 Pressure

Describe the pressure exerted on a surface by a given force.

• Pressure is defined as the magnitude of the perpendicular force component exerted per unit area over a given surface area, as described by the equation
• Pressure is a scalar quantity.
• The volume and density of a given amount of an incompressible fluid is constant regardless of the pressure exerted on that fluid.

Describe the pressure exerted by a fluid.

• The pressure exerted by a fluid is the result of the entirety of the interactions between the fluid’s constituent particles and the surface with which those particles interact.
• The absolute pressure of a fluid at a given point is equal to the sum of a reference pressure P0, such as the atmospheric pressure Patm, and the gauge pressure Pgauge. Relevant equation:
• The gauge pressure of a vertical column of fluid is described by the equation TOPIC 8.2 Pressure