Definition of Pressure (College Board AP® Physics 1: Algebra-Based)

What is pressure?

• Pressure is defined as:

Pressure is the magnitude of the perpendicular force component exerted per unit area over a given surface area

• Pressure can also be defined by the following equation:

• Where:

  • = pressure, measured in

  • = component of force perpendicular to the surface, measured in

  • = surface of the area experiencing the force, measured in

• Pressure is a scalar quantity

  • It has magnitude only, no direction

• A force acting on a surface produces a pressure

  • This force, however, may not act perpendicular to the surface

  • Only the force component which is perpendicular to the surface exerts a pressure on the surface

Force at an angle exerting pressure

Pressure in a fluid

• The surface of an object submerged in a fluid experiences pressure

• This pressure is the effect of all of the interactions between that surface and the particles of the fluid

  • This means objects in a fluid experience pressure on all sides in contact with the fluid