Principle of Buoyancy – Dependence of Upthrust According to Archimedes’ principle, the buoyant force acting on a submerged or floating body equals the weight of the liquid displaced by the body.

Introduction:
This item reviews Archimedes’ principle, a cornerstone of hydrostatics used to predict flotation, draft, and apparent weight reduction of submerged objects.

Given Data / Assumptions:

• Object immersed in a static liquid.
• Hydrostatic pressure varies with depth but is at rest.
• Gravitational field is uniform.

Concept / Approach:

Net hydrostatic pressure on a submerged surface produces an upward resultant equal to the weight of the displaced liquid. For floating bodies, this upthrust balances the body weight at equilibrium.

Step-by-Step Solution:

Verification / Alternative check:

Practical tests with hydrometers and floating vessels confirm that displacement weight equals vessel weight in equilibrium, validating the principle.

Why Other Options Are Wrong:

Pressure with which the liquid is displaced: Pressure distribution creates the force, but its integral equals the weight of displaced liquid, not the applied pressure value. Viscosity and compressibility do not determine static buoyant force in equilibrium.

Common Pitfalls:

Confusing buoyant force with drag; assuming it depends on object weight rather than displaced fluid; forgetting center of buoyancy location matters for stability but not magnitude.

Final Answer:

weight of the liquid displaced