Lecture 3: Atmosphere Pressure And Density
Atmospheric pressure is the force exerted by air molecules per unit area.
• Air is pulled downed by gravitational force; as a result, most of the air molecules are
closer to earth.
• Highest atmospheric pressure is found closer to earth, because there is a column of air
pushing down on the object.
Ideal Gas Law states that P= pRT
• P is the pressure in Pa (pascals)
• p is the air density (kg/m )
• R is the constant in (J/kgK)
• T is the temperature in Kelvin (K)
Air pressure decreases with the increasing of altitude.
• At the top of Mt. Everest, a climber would be above about 60% of the air molecules in
the atmosphere. A climber would