Net Change in Potential Energy of a Fluid

$dU = rho * dV *g*( y_2 - y_1 )$

$(rho)"Density"$

$(dV)"Volume"$

$(y_1)"Initial Height"$

$(y_2)"Final Height"$

Reference

Young, Hugh and Freeman, Roger. University Physics With Modern Physics. Addison-Wesley, 2008. 12th Edition, (ISBN-13: 978-0321500625 ISBN-10: 0321500628 ) Pg 469, eq 14.15