Air Pressure. Pressure is force pushing on an area. pressure = force area. larger force = larger pressure smaller force = smaller pressure larger area = smaller pressure smaller area = larger pressure.
larger force = larger pressure
smaller force = smaller pressure
larger area = smaller pressure
smaller area = larger pressure
Air pressure is measured in millibars or
“inches of mercury”
29.92” Hg = 1,013 mb
Average height of barometric column at sea level
pressure = force
Increasing altitude means less and less air molecules per given area. Less molecules means less pressure (force exerted) because fewer molecules collide.
Also, it’s colder up there which causes molecules to slow down and collide with less force.
Altitude increases and amount moleculesof air molecules decrease. Less air molecules per given area also mean atmosphere is less DENSE at higher altitudes.D = M V
When amount of mass in a given volume decreases, the density also decreases.
Difference in air pressure pushes water
from pan (outside) up into the glass.
High pressure area pushes towards low pressure area.
Click link below to play:
Bill Nye "Smells Like Air Pressure"