# Hydrostatic Pressure

1. Jun 22, 2009

### MyNewPony

Is the equation for hydrostatic pressure limited to liquids? Or can it be used for air pressure as well?

2. Jun 22, 2009

### Astronuc

Staff Emeritus
The concept of 'hydrostatic pressure' applies to fluids, either liquid or gas. Remember the pressure of the atmosphere decreases with increasing elevation, or increases with decreasing elevation, just as pressure in the oceans increases with depth.

Please provide the equation to which one is referring.

3. Jun 22, 2009

### MyNewPony

Sorry, here it is:

p = p0 + (rho)gh

So, I can calculate both the pressure at the bottom of an ocean and the pressure at the top of a mountain using this method?

4. Jun 22, 2009

### Andy Resnick

In the case where the density does not change with pressure. For water (an incompressible fluid), that's a good approximation. For air, that's a bad approximation.

5. Jun 23, 2009

### fawk3s

If you can get the exact density of the air on that heigth.

6. Jul 30, 2009

### mdz

i just wondering..i conduct an experiment last week on pressure inside a container.note that the container is filled with water.i've found out that the pressure on the top of the container is greater compared to the lower of the container.it's suppose to be the opposite right based on P=pgh?why does the this occured and plz correct me if i'm wrong.i used the pressure gage to take the measurement.