What does the term 'buoyancy' refer to?

Buoyancy is defined as the upward force exerted by a fluid on an object that is either submerged in the fluid or floating on its surface. This force occurs because the pressure exerted by the fluid increases with depth; therefore, the pressure on the bottom of the submerged object is greater than the pressure on the top. This difference in pressure creates a net upward force, which is what allows objects to float or, if sufficiently buoyant, to rise in the fluid.

This concept is crucial in understanding how objects behave in liquids and gases. For example, when a ship floats on water, it displaces a volume of water equal to its weight, which is why it stays afloat despite being made of metal. The amount of fluid displaced must equal the weight of the object for buoyancy to be balanced.

The other options do not accurately describe buoyancy. The downward force exerted by a fluid, for instance, is not the same as buoyancy, which is inherently an upward force. The weight of an object in a fluid pertains to its gravitational force and is influenced by the fluid’s buoyant force but does not define buoyancy itself. Lastly, the reflection of light in a fluid relates to optics and does not encompass the principles of buoy