How is the pressure of a fluid related to its density?

The relationship between the pressure of a fluid and its density is governed by the principles of fluid mechanics, particularly in hydrostatics. Pressure in a fluid increases with its density because denser fluids contain more mass per unit volume, which results in greater weight acting on any given area beneath them.

In a fluid at rest, the pressure exerted at a certain depth is a result of the weight of the fluid above that point. If the density increases, the weight of the fluid above increases, which in turn increases the pressure at that depth. This straightforward relationship demonstrates that, all else being equal, as the density of a fluid increases, its pressure at a given depth will also increase, establishing a direct proportionality.

Temperature can affect fluid density and pressure, but it does not define the inherent relationship between them under static conditions, making the connection of direct proportionality the key takeaway.