Skip to content

Pressure


Pressure

Pressure is the amount of force exerted per area.

As the temperature increases, pressure increases as the molecules strike the wall of the container more frequently and this gives a GREATER CHANGE IN MOMENTUM. As the change in momentum increases per second, the force exerted increases and therefore provides a greater pressure for a constant surface area.

Measuring pressure 

1)Mercury barometer 

The pressure at beneath a liquid surface (and therefore at the base of the mercury column) can be calculated with the following formula:
Pressure beneath liquid surface = ρgh
[ρ = density (kg/m3), g = acceleration due to gravity (10 m/s2), h = depth (m)] 

2) Manometer

Pressure due to gas = atm + ρgh
[ρ = density (kg/m3), g = acceleration due to gravity (10 m/s2), h = depth (m)]
[atm = atmospheric pressure]