On the other hand, a homogeneous, incompressible material is defined as one which has constant density throughout.

In the skin effect case another approximation is hidden in the assumption of constant current density.

With some simplifications, in particular constant density, they can be given as follows:

In particular, an isopycnic surface is a surface of constant density.

If we assume a constant density then the masses of a shell and the sphere inside it are:

An isostere is a line of constant atmospheric density.

An isopycnal is a surface of constant potential density of water.

The metal contacts are characterized by a constant density of states, filled up to the Fermi energy.

Another - often used - definition, for constant density, of the Reynolds stress components is:

Lastly, all of the above assume the air is constant density and is not moving.