Electrostatic and gravitational fields of force

Newton’s law of gravitation

The gravitational force between two particles is proportional to the product of their masses and inversely proportional to their separation squared

Coulomb’s law

The electrostatic force between two small bodies is proportional to the product of their charges and inversely proportional to their separation squared

Gravitational field strength

The force per unit mass experienced by a small test mass placed at that point

Electric field strength

The force per unit charge experienced by a small test charge placed at that point

Gravitational potential

Work done per unit mass in bringing a mass from infinity to that point

Electric potential

Work done per unit charge in bringing positive charge from infinity to that point

Equipotential

A surface on which all points are at the same potential

Escape speed

Minimum speed needed for a body to escape to infinity from a point on the surface of a mass

Field

A region of space in which a force is experienced

Magnetic field

A region of space in which a magnetic force is experienced

Electric field

A region of space in which an electric force is experienced by a charge

Gravitational field

A region of space in which a gravitational force is felt by a mass