Assumptions - Inverse Square Law

The Applet simulates the gravitational field outside and inside a sphere of uniform mass density and, in another mode, the electric field outside and inside a sphere of uniform charge density.

The applet makes the following assumptions:

A consequence of the first two assumptions is that the magnitude of the field (either electric or gravitational) accompanying the source object has the following dependence on the distance d of the field point from the center of the source: