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'''Air pressure''' is the [[scientific]] name for the [[pressure]] we experience every day due to the [[weight]] of the [[atmosphere]] (1 atm, or 760 millimeters of [[mercury]]). The typical air pressure at [[sea level]] is one atmosphere; as you climb higher, the air pressure decreases. For example, the air pressure on top of [[Mount Everest]] is less than the air pressure on top of [[Mount McKinley]].
Air pressure is used by modern industry, in the form of [[pneumatic engine]]s. [[Hydraulic engine]]s are similar to pneumatic engines, but use [[water pressure]] instead of air pressure. The brake lines in your [[car]] are probably pneumatic — which is to say, your very life may depend on air pressure!
