# Why do warm gases/liquids rise and cool gases/liquids fall?

Jun 30, 2017

This is a manifestation of $\text{Archimedes' Principle......}$

#### Explanation:

And is also the reason why solids and liquids that are less dense than water, FLOAT on water.......

$\text{Archimedes' Principle states that......}$

$\text{...a body immersed in a fluid experiences a buoyant force equal}$ $\text{to the weight of the fluid it displaces.........}$

A gas or a liquid (a fluid in fact) that is WARM necessarily occupies more volume than a colder fluid. This is especially true for gases, where volume is a state function of temperature......$V \propto T$.

And this is also the basis of the hot-air balloon, where the hot gas inside the balloon displaces a mass of air that is greater than the mass of balloon and the basket, and so the balloon floats.