# Formula Hydrostatic pressure Hydrostatic pressure Density Height / Depth Gravitational acceleration

## Hydrostatic pressure

`$$ \mathit{\Pi} $$`Unit

`$$ \frac{ \mathrm{N} }{ \mathrm{m}^2 } $$`

Pressure of the fluid at depth \( h \) or of the gas at height \(h\). The fluid (e.g. water) or the gas (e.g. air) exerts a certain force on a square meter.

## Density

`$$ \rho $$`Unit

`$$ \frac{ \mathrm{kg} }{ \mathrm{m}^3} $$`

Density of the fluid or gas on which the hydrostatic pressure \(\Pi\) acts. The denser the fluid or gas, the greater the hydrostatic pressure.

For example, the density of water is: \( 997 \, \frac{ \mathrm{kg} }{ \mathrm{m}^3 } \) and the density of ethanol: \( 789 \, \frac{ \mathrm{kg} }{ \mathrm{m}^3 } \). Thus, at the same depth \(h\), a greater hydrostatic pressure is established in water than in ethanol.

## Height / Depth

`$$ h $$`Unit

`$$ \mathrm{m} $$`

In the case of fluid (e.g. water), it is the depth measured from the bottom of the sea. In the air atmosphere, for example, it is the height above the ground. In a test tube, it is the height measured from the bottom of the test tube.

## Gravitational acceleration

`$$ g $$`Unit

`$$ \frac{\mathrm{m}}{\mathrm{s}^2} $$`

Acceleration experienced by any body on Earth. Acceleration due to gravity has the value: \( g = 9.8 \, \frac{\mathrm m}{ \mathrm{s}^2 } \).