Two satellite A and B of the same mass are revolving around the Earth in circular orbits such that the distance of B from the centre of the Earth is thrice as compared to the distance of A from the centre. What will be the ratio of centripetal force on B to that on A.

Explanation

The necessary centripetal force is provides by the gravitational force of attraction , for circular orbit
Force on A ,`(mv^(2))/r = (GMm)/(r^(2))`
Force on B , `(mv^(2))/r = (GMm)/(3r)^(2)`
The ratio of centripetal force ,
`(F_(B))/(F_(A)) = (GMm)/(9r^(2)) xx (r^(2))/(GMm)`
`(F_(B))/(F_(A)) = 1/9 `