Newton's Law of Universal Gravitation states that every particle in the universe attracts every other particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

This can be expressed by the formula:

F = G * (m1 * m2) / r^2

Where F is the gravitational force between two objects, G is the gravitational constant (approximately 6.67430 x 10^-11 N * m^2 / kg^2), m1 and m2 are the masses of the two objects, and r is the distance between their centers of mass.

For example, consider two objects: a 2 kg ball and a 5 kg ball placed 3 meters apart. Plugging the values into the formula, we can calculate the gravitational force between them.

F = (6.67430 x 10^-11 N * m^2 / kg^2) * ((2 kg) * (5 kg)) / (3 m)^2

F = 1.863 x 10^-10 N

The gravitational force between the two balls is approximately 1.863 x 10^-10 Newtons.