An object satisfying the hydrostatic law is said to be in hydrostatic equilibrium.
A slab with two layers in hydrostatic equilibrium satisfies
Solving for
Hydrostatic Law, Law of Atmospheres
References
Turcotte, D. L. and Schubert, G. Geodynamics: Applications of Continuum Physics to Geological Problems. New York: Wiley, 1982.
