• A fluid is either a?liquid?or a?gas
• When an object is immersed in a fluid, the fluid will exert pressure, squeezing the object
  • This pressure is exerted evenly across the whole surface of the fluid and in?all directions
  • The pressure exerted on objects in fluids creates?forces?against surfaces
  • These forces act at?90 degrees?(at right angles) to the surface

   

The pressure of a fluid on an object creates a force normal (at right angles) to the surface

• The pressure due to a column of liquid can be calculated using the equation

p?=?h?× ρ ×?g

• Where:
  • p?= pressure in pascals (Pa)
  • h?= height of the column in metres (m)
  • ρ?= density of the liquid in kilograms per metre cubed (kg/m³)
  • g?= gravitational field strength on Earth in newtons per kilogram (N/kg)

   

• The force from the pressure is exerted evenly across the whole surface of an object in a liquid, and in?all?directions

The force from the pressure of objects in a liquid is exerted evenly across its whole surface

• The pressure is more accurately the?difference?in pressure at different depths?h?in a liquid, since the pressure changes with the depth