Archimedes’ Principle is a fundamental law of physics that explains why objects float or sink in a fluid. It states that:
The buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid the object displaces.
This principle applies to all fluids—liquids and gases—and to both fully and partially submerged objects.
How It Works:
- When an object is placed in a fluid, it pushes some of the fluid out of the way (displaces it).
- The fluid responds by exerting an upward buoyant force on the object.
- If this force equals the object’s weight, it floats; if it’s less, the object sinks; if it’s more, the object rises.
Examples:
- A wooden log floats because it displaces a volume of water whose weight equals the weight of the log.
- A submarine adjusts its buoyancy by controlling how much water it displaces.
- Hot air balloons rise by displacing cooler, denser air with warmer, lighter air inside the balloon.
Archimedes’ Principle is essential in understanding fluid statics, naval architecture, and hydrostatics, forming the basis for technologies like ships, submarines, hydrometers, and even airships.