If the distance between two point particles is doubled, then the gravitational force between them

Options

A. decreases by a factor of 4
B. decreases by a factor of 2
C. increases by a factor of 2
D. increases by a factor of 4

Answer

A

Explanation

Gravitational force obeys an inverse-square law : `F_("grav") prop (1)/(r^(2))`. Therefore, if r increases by a factor of 2, then `F_("grav")` decreases by a factor of `2^(2)=4`.