Which principle explains that the upward buoyant force equals the weight of displaced fluid?

Which principle explains that the upward buoyant force equals the weight of displaced fluid?

• A. ARCHIMEDES PRINCIPLE
• B. PASCAL'S LAW
• C. BOYLE'S LAW
• D. NEWTON'S THIRD LAW

Answer: (A)

Archimedes' principle explains buoyancy: the upward buoyant force on a body submerged in a fluid equals the weight of the fluid displaced by the body. This happens because fluid pressure increases with depth, so the pressure push from below is greater than the pressure push from above, creating a net upward force. The buoyant force can be calculated as F_b = ρ_fluid · g · V_submerged, where ρ_fluid is the fluid density, g is gravity, and V_submerged is the submerged volume. This is why objects float or sink depending on whether their weight is balanced by the weight of the displaced fluid: if the object's weight is less than the buoyant force, it rises and displaces more fluid until in equilibrium; if heavier, it sinks. Other principles don’t describe this upward force: Pascal's law concerns pressure transmission in fluids, Boyle's law relates pressure and volume in gases, and Newton's third law is about action-reaction forces, not buoyancy.

Archimedes' principle explains buoyancy: the upward buoyant force on a body submerged in a fluid equals the weight of the fluid displaced by the body. This happens because fluid pressure increases with depth, so the pressure push from below is greater than the pressure push from above, creating a net upward force. The buoyant force can be calculated as F_b = ρ_fluid · g · V_submerged, where ρ_fluid is the fluid density, g is gravity, and V_submerged is the submerged volume. This is why objects float or sink depending on whether their weight is balanced by the weight of the displaced fluid: if the object's weight is less than the buoyant force, it rises and displaces more fluid until in equilibrium; if heavier, it sinks. Other principles don’t describe this upward force: Pascal's law concerns pressure transmission in fluids, Boyle's law relates pressure and volume in gases, and Newton's third law is about action-reaction forces, not buoyancy.