Our earth has gravitation. The gravitation is a kind of force. The gravitational force is a force that attracts any objects with mass towards the centre of the earth.

The Newtons Universal law of gravitation states that the gravitational force is directly proportional to the mass of the object and inversely proportional to the square of the distance between them.

Consider two masses of m₁ and m₂ which are at a distance of r apart. Then by the Newtons Law of gravitation, F = G m₁ m₂ / r² where G is the gravitational constant.