Calculating Pressure in a Liquid (Edexcel GCSE Physics)

Calculating Pressure in a Liquid

Higher Tier Only

• 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