Important Equations

m2 = mass 2

m1 = mass 1

M = mass of the planet

g = acceleration due to gravity

F1 = The force m1 feels from m2

F2 = The force m2 feels from m1

G = Gravitational constant

G = 6.67300
× 10^{-11} m^{3} kg^{-1} s^{-2 }

r = distance between m1 and m2

Newton's
law of universal gravitation is about the
**universality** of gravity. **ALL** objects attract
each other with a force of gravitational attraction. Gravity
is universal. This force of gravitational attraction is
directly dependent upon the masses of both objects and
inversely proportional to the square of the distance which
separates their centers.

Definition provided by physics classroom

Newton's Law of Universal Gravity