Question
How does the gravitational force change between two objects when:
(i) the distance between them is reduced to half,
(ii) the mass of each is reduced to half. Justify your answer in each case.
Solution
As per Newton's law of gravitation, the force of attraction between two bodies is given by,
(i) Here, distance between the bodies is reduced to half.
i.e., 
i.e, gravitational force increases four times when distance is reduced to half.
(ii) Given, mass of each body is reduced to half.
That is,
Hence, the gravitational force becomes one-fourth of the original value.
