In
physics, buoyancy is the upward
force on an object produced by the surrounding
fluid (i.e., a
liquid or a
gas) in which it is fully, or partially immersed, due to the
pressure difference of the fluid between the top and bottom of the object. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. This force enables the object to float or at least to seem lighter. Buoyancy is important for many
vehicles such as
boats,
ships,
balloons, and
airships.
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