Question

A plastic sphere has a density that is greater than oil but less than water when itis placed in cylinder containing water, it is exactly half submerged, explain why when oil poured on top of water. The sphere is only 1/4 submerged in water.

Answer 1

The density of the sphere is 1/2 of the density of water. But when oil is added to the water, the resulting solution has a density twice that of water. So the new density ratio is 1/4.