Gravitation and electric fields

Newton's Law of Universal Gravitation

Every particle with mass in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Gravitational field

The force acting per unit mass. It is described as a region in space where a mass will experience a force.

Coulomb's law

Two point charges in free space or air exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges.

Magnitude of an electric field at a point

The force per unit positive charge.