You hold a piece of wood in one hand and a piece of iron in the other. Both pieces have the same volume, and you hold them fully under water at the same depth. At the moment you let go of them, which one experiences the greater buoyancy force?

(a) The piece of wood.

(b) The piece of iron.

(c) They experience the same buoyancy force.

(d) More information is needed.

The buoyancy force can be described as a force that acts on a body in the vertically upward direction when the body is partially or fully immersed in a liquid. Buoyancy force depends on the density of the liquid, the volume of the body that enters into the liquid, and gravitational acceleration.

The buoyancy force on the body is given by the expression,

F_b = ρ₁ V₁g

Here,F_b is the buoyancy force, ρ₁ is the density of the liquid, V₁ is the volume of the body immersed in the liquid and g is the gravitational acceleration.

The buoyancy force is independent of the mass and the density of the body only depends on the density of the liquid, the body’s volume inside the liquid, and gravitational acceleration. Since both bodies, iron, and wood, have equal volume and lie at the same depth under the same water, both bodies (iron and wood) experience the same buoyancy force.

Thus, from the above analysis, option (c) is correct.