$$\rightleftharpoonup{xx}$$
$$\longleftharp{xx}$$,
$$\longrightharp{xx}$$,
Have you ever wondered how a huge cruise ship floats on water while a small rock sinks to the bottom? The answer lies in Archimedes’ Principle, discovered over 2000 years ago by a Greek scientist named Archimedes.
Archimedes found that when an object is placed in water, it pushes water aside. This is called displacement.
This displaced water pushes back on the object with an upward force called the buoyant force.
If the buoyant force equals or exceeds the object's weight, it floats. If not, it sinks.
A cruise ship floats because its large, hollow shape lowers its average density, allowing it to displace more water and create sufficient buoyant force.
A solid steel ball sinks because it is small and dense, and it does not displace enough water to create enough buoyant force to hold it up.
You can even test this in a bathtub. A steel ball sinks, but a steel toy boat of the same weight floats.
Today, Archimedes' Principle helps engineers to design boats, submarines, and floating bridges.
