Question

Two life preservers have identical volumes, but one is filled with Styrofoam while the other is filled with sand. When the two life preservers are worn by swimmers so that one swimmer floats with part of the preserver above water, and the other swimmer sinks, the buoyant force is actually greater on the life preserver filled with _________.

Answer 1

Answer:

Sand

Explanation:

While the term buoyancy may confuse the reader, the question here is referring to buoyant force.

Buoyant force is the amount of pressure exerted on an object by the liquid it is in. Given by the formula

$F_{b} = V_{o} D_{l} g$

Where

$F_{b}$ = Buoyant Force

$V_{o}$ = Volume of Object submerged in the liquid

$D_{l}$ = Density of Liquid

$g$ = Force of gravity

Since in this question the swimmer with the sand is completely submerged in water, more of the volume of his preserver is under the water hence the buoyant force is greater on it than the swimmer with the Styrofoam (as part of him is not submerged in water)