The Archimedes Principle: Once upon a time, a man named Archimedes was tasked with figuring out how to tell if a crown was made of gold or if it was a fake - without ruining it. Because of the crown's odd shape, he didn't know its volume to tell how dense it was. One day, Archimedes took a bath and noticed that the bathwater rose according to how much of his body was in the water. The volume of the submerged part of his body was the same volume as the water that rose out of the way - or, in other words, was displaced. He realized that he could determine the crown's volume this way and compare its weight to the same volume of pure gold to see if they weighed the same. This idea struck him so much that he ran naked through the town shouting, "Eureka!" This lightbulb moment led to Archimedes' Principle.

In simple form, the Archimedes law states that the buoyant force on an object is equal to the weight of the fluid displaced by the object. Mathematically written as:

Fb = ρ × V × g

... where Fb is the buoyant force, ρ is the density of the fluid, V is the volume of the object submerged, and g is the acceleration due to gravity

Archimedes' principle (also spelled Archimedes's principle) states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces.Archimedes' principle is a law of physics fundamental to fluid mechanics.