Pressure (usually denoted by ) is measured as the distributed force over an area/surface.

Definition

While the idea of forces is a useful concept, a more realistic concept is pressure, which helps explain why bullets are so strong, while falling flat on a pool of water hurts so much, why drills are always cone shaped, etc.

Pressure applies to all states of matter: solids as well as fluids (gasses and liquids)

Calculating Pressure

  • = Pressure (in Pascals, Pa or Newton-Metres squared, Nm²)
  • = Force (in Newtons, N)’
  • = Area (in metres squared, m²)

Since area is inversely proportional to pressure, objects with smaller surface area (such as pointed tips) will always have a greater pressure than flat surfaces.

Pascal’s Principle

Vital in Hydraulics & Pneumatics, Pascal’s Principle states that:

Pressure exerted anywhere in a confined fluid is transmitted equally in all directions throughout the fluid.

Again, fluids here refers to both liquids and gases.