The gravitational constant, G, is utterly important for any engineer. It is approximately 6.674×10−11 m3⋅kg−1⋅s−2 and helps determine the force between two masses. It appears in Newton‘s law of universal gravitation and Einstein‘s general theory of relativity. According to Newton, it is the proportionality constant connecting the gravitational force between two bodies with the product of their masses and the inverse square of their distance.

## Boltzmann’s Constant

The fundamental constant of physics, the Boltzmann constant, is one of the seven "defining constants" that have been given exact definitions.