please help me do this mechanics problem?

Question

Two cylindrical vessels of equal crosssectional area 'A' contain water upto heights 'H1' and 'H2'. The vessels are interconnected so that the levels in them become equal. Calculate th work done by the force of gravity during the process. The density of water is P

Answer 1

The liquid will level, so the volume of liquid that moves is
V = [(H1-H2) / 2] x A
The weight is V x P
The rest, you should know.