Temperature & Pressure (CIE IGCSE Physics: Co-ordinated Sciences (Double Award))

• As the temperature of a gas increases, so does the average speed of particles in the gas
  • At higher temperatures, the particles have more kinetic energy
• The amount of pressure that a gas exerts on its container is dependent on the temperature of the gas
  • This is because particles gain kinetic energy as their temperature increases

Extended tier only

• Gases fill their container
• The pressure is defined as the force per unit area

• Where:
  • = pressure in pascals Pa
  •  = force in newtons N
  • = area in metres-squared m²
• This equation and the particle model can be used to explain how particles exert pressure
• As the gas particles move about randomly they collide with the walls of their containers
• These collisions produce force at right angles to the wall of the gas container (or any surface)
  • Pressure is force per unit area, so the force of these collisions exerts a pressure

Gas molecules bouncing off the walls of a container exert a force perpendicular to the surface