Buoyant force is the upward force exerted by a fluid on an object that is either fully or partially submerged in it. This force occurs because the pressure in a fluid increases with depth. As a result, the bottom of an object submerged in a fluid experiences more pressure than the top, creating a net upward force.
This principle is described by Archimedes’ Principle, which states that the buoyant force on an object equals the weight of the fluid it displaces.
Key Features:
- Acts opposite to the force of gravity.
- Responsible for making objects float, sink, or remain neutrally buoyant.
- Depends only on the volume of fluid displaced, not the object’s material.
Examples:
- A boat floats because it displaces a volume of water equal to its weight.
- A helium balloon rises in air because the buoyant force exceeds the weight of the balloon.
- A diver feels lighter underwater due to the upward buoyant force acting on their body.
Buoyant force plays a critical role in fluid mechanics, ship design, underwater exploration, and atmospheric science, influencing how objects behave in liquids and gases.