Question

suppose that two objects attract each other with a gravitational force of 16units. if the distance between the two objects is doubled, what is the new force of attraction between the two objects?

Answer 1

$$F_{new}=\dfrac{Gm_1m_2}{(2d)^2}=\dfrac{Gm_1m_2}{4d^2}=\dfrac{1}{4}\dfrac{Gm_1m_2}{d^2}=\dfrac{F}{4},$$ $$F_{new}=\dfrac{16\ units}{4}=4\ units.$$