A steel ball sinks in water but floats in a pool of mercury, which is much denser than water. Where is the buoyant force on the ball greater?
A) floating on the mercury
B) It is the same in both cases.
C) submerged in the water
D) It cannot be determined from the information given.

Question

Quizplus · Accepted Answer

The buoyant force on the ball is greater when it is floating on the mercury because the buoyant force is equal to the weight of the fluid displaced by the object. Since mercury is denser than water, the ball displaces a greater weight of mercury than it would displace water if it were submerged, resulting in a greater buoyant force.

A Steel Ball Sinks in Water but Floats in a Pool