According to the universal law of gravitation, there will be a force of attraction between two particles that is directly proportional to the product of the masses of the respective particles and inversely proportional to the square of the distance between the two particles.
The expression for the gravitational force is given as, . Here, is the universal gravitational constant, and are the mass of the particles and is the distance between the particles.
The universal law of gravitation was formulated by Isaac Newton in .