Knowra Buoyancy Buoyancy Buoyancy is the upward force a fluid exerts on an immersed or floating object. In a static fluid, it equals the weight of the fluid displaced by the object.
Archimedes' principle : A principle stating that an immersed body experiences an upward force equal to the weight of the fluid it displaces. It gives the standard rule for calculating buoyant force.
Ship stability : A vessel's ability to resist capsizing and return toward an upright position after disturbance. The relative positions of the center of buoyancy and center of gravity determine restoring motion.
Drag force : A force that opposes an object's motion through a fluid. Drag depends on motion relative to fluid, unlike buoyancy, which can act at rest.
Crown of Hiero : A legendary test in which Archimedes supposedly used water displacement to investigate whether a crown was pure gold. The story links buoyancy and displacement to measuring an object's volume and density.
Density : Mass per unit volume of a substance. The object's and fluid's densities determine whether the object floats, sinks, or remains suspended.
Hydrostatic pressure : Pressure exerted by a fluid at rest, increasing with depth in a uniform gravitational field. Greater pressure on an object's lower surfaces produces a net upward force.
Submarine : A watercraft designed to operate underwater, often controlling depth by changing the water in its ballast tanks. Adjusting displaced water lets a submarine change its buoyancy and depth.
Lift (force) : A force perpendicular to an object's motion through a fluid, commonly generated by pressure differences around a wing. Lift and buoyancy both arise in fluids, but lift usually depends on flow and motion.
Iceberg : A large mass of freshwater ice that has broken from a glacier or ice shelf and floats in the ocean. Its mostly submerged form illustrates how floating depth depends on relative densities.
Fluid : A substance that flows and continuously deforms under applied shear stress, including liquids and gases. Buoyancy is a force exerted by fluids, not only by water.
Show all 27