Air pressure

6.3  Air pressure
The Earth is surrounded by a layer of air known as the Earth's atmosphere. Air consists of particles that are always moving freely in all directions and collide with the walls of the environment or walls of the container.
Air Pressure
  Air pressure results from the collision of air particles on the surface of an object  

The relationship between air pressure and altitude

  • Air pressure varies from place to place
  • The air pressure at the top of the mountain is lower than the air pressure at the foot of the mountain
  • Air pressure decreases when at a higher altitude
  • The number of air particles decreases when being in a higher position
Air Pressure Application
  • When air is inhaled, the area inside the straw creates a low pressure area. The higher air pressure outside will push the water into the straw.
  • When the plunger is pressed, there is low pressure inside the plunger and causes the air in the plunger to come out. The higher pressure in the sinkhole pushes out the clogged waste when the plunger is pulled up.