Question

The gravitational force between two objects is 1600 N. What will be the gravitational force between the objects if the distance between them doubles?
A.)400 N
B.)800 N
C.)3200 N
D.)6400 N

Answer 1

The gravitational force is inversely proportional to squared distance.
This means when the distance between the objects is increased, the gravitational force reduces. 

1600 = k/d². where k is constant.
k=1600d²

When d is doubled, the gravitational force, F,

F = 1600d²/(2d)²
F = 400 N