Buoyancy refers to the ability of a fluid (liquid or gas) to exert an upward force on an object immersed in it. This upward force, called the buoyant force, is what makes objects appear lighter in water than in air, and can cause objects to float. The property of a fluid to exert this upward force is buoyancy.
Here’s a more detailed explanation:
Buoyant Force:
The upward force exerted by a fluid on an object submerged in it.
Why it happens:
Pressure in a fluid increases with depth. The pressure at the bottom of an object submerged in a fluid is greater than the pressure at the top, resulting in a net upward force.
Archimedes’ Principle:
The buoyant force on an object is equal to the weight of the fluid displaced by the object.
Floating vs. Sinking:
An object floats if the buoyant force is greater than or equal to its weight. If the buoyant force is less than the object’s weight, the object sinks.
Examples:
A boat floats because the buoyant force (due to the displacement of water) is greater than its weight. A rock sinks because the buoyant force is less than its weight.