Pressure

• Pressure can be calculated using the formula P = F/A, where P is pressure, F is force, and A is area.
• Pressure in a liquid equation

  P = H x p x G, where P is pressure, H is height, p is density and G is Gravity.
• Weight (W) = Mass (M) x Gravitational field strength (g).
• Reason for aircraft pressurisation

  If the air pressure is too low, humans cannot take in oxygen quickly enough to meet their bodies’ needs
• Reasons why atmospheric pressure decreases the higher up you go

  Less air molecules meaning less weight being exerted
• Complex Equation for water pressure

  1. Volume of liquid= (Pi x r^2 x Height)
  2. Mass of liquid= (Volume x Density)
  3. Weight of liquid= (Mass x Gravity)
  4. Pressure = (Weight/Cross-section)
• SI unit for pressure: Pascal (Pa)
• Pressure decreases the higher up you go as there are less air molecules exerting a downward force, therefore less pressure
• Pressure increases as you go deeper in water as there are more water molecules exerting a downward force on an object
• Pressure

  The amount of force applied per unit area
• Atmospheric pressure refers to the weight of air pressing down on Earth's surface and can be measured using a barometer.
• Collisions of molecules (gas or liquid) on a surface produce pressure