Important Points about Gravitation Force ( i ) Gravitational force is a central as well as conservative force .
( ii ) It is the weakest force in nature .
( iii ) It is 1036 times smaller than electrostatic force and 10 ’ l8times smaller than nuclear force .
( iv ) The law of gravitational is applicable for all bodies , irrespective of their size , shape and position .
( v ) Gravitational force acting between sun and planet provide it centripetal force for orbital motion .
( vi ) Gravitational pull of the earth is called gravity .
( vii ) Newton ’ s third law of motion holds good for the force of gravitation . It means the gravitation forces between two bodies are action-reaction pairs .
Following three points are important regarding the gravitational force
( i ) Unlike the electrostatic force , it is independent of the medium between the particles .
( ii ) It is conservative in nature .
( iii ) It expresses the force between two point masses ( of negligible volume ). However , for external points of spherical bodies the whole mass can be assumed to be concentrated at its centre of mass .
Note Newton ’ s law of gravitation holde goods for object lying at uery large distances and also at very short distances . It fails when the distance between the objects is less than 10-9 m i . e ., of the order of intermolecular distances .