Answer: Weight of fluid displaced by the object.
- A Weight of fluid displaced by the object
- B Weight of the object
- C Volume of fluid displaced times g
- D Density of fluid times volume of object
Correct answer: A. Weight of fluid displaced by the object
Explanation: Buoyant force = weight of fluid displaced = ρ_fluid × V<sub>submerged</sub> × g. This is Archimedes' principle.
Since the same volume of fluid must pass every cross-section per second (continuity), the fluid speeds up where the pipe narrows; Bernoulli's equation then says this faster-moving fluid has lower pressure - the principle behind a venturi meter and an aircraft wing's lift.
Concept context
Pressure, buoyancy, Bernoulli equation, viscosity, and surface tension.