• Pressure is defined as the force per unit area on a surface.
  • Earth’s atmosphere exerts pressure because gravity acts on the huge number of gas particles contained in the atmosphere, holding it in place.
  • Pressure is also exerted by a small sample of gas, such as that which is contained in a balloon.
  • Gas pressure is the pressure that results from collisions of gas particle with an object.
  • The pressure inside the hot air balloon is affected by temperature.
  • As the molecules heat up, they move faster and strike the inside wall of the balloon harder.
  • This increased motion of the gas particles increases the force on an area of the balloons.
Select from the frequently asked questions below