Universal Gravitation and Gravitational Field

All massive objects attract each other with

a gravitational force

The gravitational force Fg of one object on another is given by

Fg= G m1m2/r²

r

distance between the centers of the two objects

G

 universal gravitation constant, 6.67 × 10^-11

N(m)^²/kg²

The gravitational force between two objects or systems is

directly proportional to each of their masses

inversely proportional to the square of the distance between the systems’ centers of mass. 

The gravitational field g near an object of mass M is given by

G=G m/r² where r represents the distance from the object’s center to anywhere you’re considering.

The weight of an object near a planet is given by

 mg

The gravitational field near a planet is always equal

To the free-fall acceleration.