In nuclear fission and nuclear fusion reactions, the amount of mass converted to energy of other forms is

Mass defect

Explanation:

The Nucleus of an atom is made of neutrons and protons. The energy needed in keeping the neutrons and protons of an atom’s nucleus intact is called Nuclear binding energy. The total mass of an atom’s individual protons and neutrons greater than the mass of its nucleus. This difference in mass is called mass defect. Mass defect can be attributed to Nuclear binding energy in an atom’s nucleus.

During a nuclear reaction (fusion or fission) nuclear energy is released which is due to the mass defect and is released in the form of photons, neutrons etc.

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered

this could be newton#'s law of cooling. the cooling curve is exponential