Their Gravity Theory

The formula for force is:

F = ma


The formula for the force of gravity is:


Fg = GMm ⁄  r ²


The force of gravity between the Earth and a body on its surface is the weight of the body.


The formula for kinetic energy is:


KE = ½ mv ²


The formula for gravitational potential energy is:


GPE = –GMm  ⁄  r


They get this formula by integrating the formula for the force of gravity.

Mechanical energy is equal to kinetic energy plus gravitational potential energy. The formula for mechanical energy is:


ME = ½ mv ² − GMm  ⁄  r