where F ′ is the external force, G is gravitational constant and r is the distance between massesM andm.Wecan integrate Eq.
(10) with displacement to get the total kinetic energy of the detached mass which is the difference in change in Hamiltonian
and its potential energy. Thus, we can again get the equation of entropy in terms of Eq. (4).
The potentials and conservative fields which play a vital role in entropy reduction in the context of gases have
electromagnetic origins. A set of gas molecules enclosed in a metallic chamber expand under application of heat resulting
in an increase in entropy. However, when heat is applied to the gas by a pulse of electrical energy through a negatively
charged electrode having a total charge Q as shown in Fig. 4, then, the gas molecules are subjected to a repulsive force due
to mutual electrostatic repulsion of the charged molecules and attracted by the negatively charged electrode at the centre.
We assume that such that the electrons of the gas molecules are knocked off and reach the inner surface of the spherical
shell from where they appear on the outer edge which is grounded. The net force on a sample of n molecules each having a
charge qi is given by