Why does air have pressure?
1 Answer
May 31, 2017
Air has pressure because it has weight under gravity.
Explanation:
Air pressure exists because air has mass. If you imagine a square metre of land. It has a column of air above it one square metre in cross section going from ground level all the way up to where the atmosphere stops.
This column of air has a mass of about 10,000Kg. This exerts a force of about 10,000 N due to its weight under gravity.
The unit of air pressure is the Pascal or Pa.
The average air pressure at sea level is 101,325Pa.
Air in a container, like any gas, also has a pressure due to the air molecules bouncing off the container walls.
