Question

A cube of side 5 cm is immersed in water and then in a saturated salt solution. In which case will it experience a greater buoyant force. If each side of the cube is reduced to 4 cm and then immersed in water, what will be the effect on the buoyant force experienced by the cube as compared to the first case for water. Give a reason for each case.

Answer 1

The cube will experience a greater buoyant force in saturated salt solution than in water as the density of the saturated salt solution is greater than that of water.
As buoyant force = weight of the liquid displaced by the object =Vag (a is the density of liquid) As each side of the cube is reduced to 4 cm from 5 cm, so the volume of the cube decreases and hence the buoyant force also decreases.