Which statement correctly describes buoyant force on a submerged object?

Which statement correctly describes buoyant force on a submerged object?

• A. Acts upward with magnitude equal to the weight of displaced fluid
• B. Acts downward with magnitude equal to the weight of displaced fluid
• C. Acts upward equal to the weight of the object
• D. Acts sideways equal to the density times the submerged volume

Answer: (A)

Buoyant force is the upward push the surrounding fluid exerts on a body immersed in it. This upward push comes from the pressure increasing with depth: the bottom surface feels greater pressure than the top, so when the pressure forces are added up, the net vertical force points upward. Its magnitude equals the weight of the fluid that would occupy the submerged volume of the object. In formula form, F_b = ρ_fluid g V_submerged. This is why the buoyant force is directed upward and has a strength equal to the weight of the displaced fluid. It’s not a downward force, not the weight of the object, and not a sideways quantity; the weight of the displaced fluid captures both the direction and the correct magnitude.

Buoyant force is the upward push the surrounding fluid exerts on a body immersed in it. This upward push comes from the pressure increasing with depth: the bottom surface feels greater pressure than the top, so when the pressure forces are added up, the net vertical force points upward. Its magnitude equals the weight of the fluid that would occupy the submerged volume of the object. In formula form, F_b = ρ_fluid g V_submerged.

This is why the buoyant force is directed upward and has a strength equal to the weight of the displaced fluid. It’s not a downward force, not the weight of the object, and not a sideways quantity; the weight of the displaced fluid captures both the direction and the correct magnitude.