Question

What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?

Answer 1

According to the universal law of gravitation, the force of gravitation between two objects is given by

\(𝐹 \,=\, \frac{𝐺𝑀𝑚}{𝑟^2}\)

(i) F is directly proportional to the masses of the objects. If the mass of one object is doubled, then the gravitational force will also get doubled. 

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(ii) F is inversely proportional to the square of the distances between the objects. If the distance is doubled, then the gravitational force becomes one-fourth of its original value. 
Similarly, if the distance is tripled, then the gravitational force becomes one-ninth of its original value.

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(iii) F is directly proportional to the product of masses of the objects. If the masses of both the objects are doubled, then the gravitational force becomes four times the original value.