Editing Flight (section)

==== Buoyancy ====
{{Main|Buoyancy}}
Air pressure acting up against an object in air is greater than the pressure above pushing down. The buoyancy, in both cases, is equal to the weight of fluid displaced - [[Archimedes' principle]] holds for air just as it does for water.

A cubic meter of air at ordinary [[atmospheric pressure]] and room temperature has a mass of about 1.2 kilograms, so its weight is about 12 [[Newton (unit)|newtons]]. Therefore, any 1-cubic-meter object in air is buoyed up with a force of 12 newtons. If the mass of the 1-cubic-meter object is greater than 1.2 kilograms (so that its weight is greater than 12 newtons), it falls to the ground when released. If an object of this size has a mass less than 1.2 kilograms, it rises in the air. Any object that has a mass that is less than the mass of an equal volume of air will rise in air - in other words, any object less dense than air will rise.