The formula for force is:

F = ma

The formula for the force of gravity is:

Fg = GMm / r ²

G is a constant, M and m are the masses of two bodies, r is the distance between their centers.

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

Between every particle of matter of one body and every particle of matter of another body is a gravity bond. The total strength of all the gravity bonds between two bodies is the weight of either body.

When energy goes up, bonds get weaker. When energy goes down, bonds get stronger.

When energy goes up, bonds get weaker. When energy goes down, bonds get stronger.

The formula for kinetic energy is:

KE = ½ mv ²

When kinetic energy goes up, gravity bonds get weaker.

The rest weight of a body is how much the body weighs when it isn’t moving. The formula for rest weight is:

RW = GMm / r

The formula for weight is:

W = GMm / r − ½ mv ²