A body of volume v and density p is initially suberged in a liquid of density o. It is lifted through a height h in the liquid. Its potential energy

Resultant downward force on the body isF=vρg−vσg=v(ρ−σ)g When it is liffed uP, then workdoae =Force x distance or W=V(ρ−σ)g×h Therefore, potential energy increases by hv(ρ−σ)g