Archimedes Principle            archimedes

Principle of buoyancy which explains that when an object is immersed in a fluid, it appears to become lighter because there is an upward buoyant force exerted on the object. The buoyant force is equal to the mass of water displaced by the object. The object will float if the buoyant force exceeds the mass of the object, and sink if the mass exceeds the buoyant force.