• id: JME-09-N04
• title: Buoyancy and Archimedes' Principle
• tags: buoyancy, archimedes, floating

A body immersed in a fluid experiences an upward buoyant force equal to the weight of displaced fluid: $F_B = \rho_f V_{\text{sub}} g$. The buoyant force acts at the center of buoyancy (centroid of the displaced fluid volume). Conditions: floats if $\rho_{\text{body}} < \rho_{\text{fluid}}$ (fraction submerged = $\rho_b/\rho_f$); sinks if $\rho_b > \rho_f$; neutral buoyancy if $\rho_b = \rho_f$. Apparent weight in fluid = true weight $-$ buoyant force = $mg - \rho_f V g$. For a floating body, the apparent weight is zero (weight equals buoyancy).