Following are the main features of gravitational force:
(i) It is always an attractive force.
(ii) It is independent of the medium between the particles
(iii) It holds good over a wide range of distances (i.e., from interplanetary distances to inter-atomic distances.)
(iv) It is an action-reaction pair, i.e., the force of attraction exerted by body A on body B is equal to the force of attraction exerted by body B on body A. However, the acceleration of the two bodies will not be equal.
(v) The gravitational force between two particles is independent of presence or absence of other particles.
(vi) The total gravitational force on one particle due to number of particles is the resultant of forces of attraction exerted on the given particle due to individual particles, i.e.,
F = F1 + F2 + F3 + .............
It proves that the principle of superposition is valid.
(vii) It expresses, the force between point masses.
(viii) It is a conservative force, i.e., the work done in moving a particle once around a closed path under the action of gravitational force is zero.
