State the universal law of gravitation.
The universal law of gravitation states that everybody in the universe attracts every other body by the virtue of its mass. This force is directly proportional to the product of the masses of the two bodies and inversely proportional to the square of the distance between them.
Let there be two bodies of masses m1 and m2 and let the distance between them be r. The gravitational force Fg between them would be given by
where G is the universal gravitational constant and is equal to