Question

What happens to the gravitational force between two object:-
1. If the distance between the object is tripled
2. The masses of both objects are doubled

Answer 1

1. Force become 1/9 times.

2. Forces become 4 times.

Answer 2

Relation:  

F is inversely proportional to R^2

and, F is directly proportional to product of masses.

1) If distance is doubled then, 3R^2 = 9R^2

Force will be reduced to 1/9 times.

2) If both masses are doubled then, 2m1*2m2 = 4m1m2

Hence, Force will increase to 4 times.