Physics Question

Question

A 6.8 kg bowling ball and a 6.3 kg bowling ball rest on a rack 1.26 m apart.

(a) What is the force of gravity exerted on each of the balls by the other ball?

(b) At what separation is the force of gravity between the balls equal to 2.0 10-9 N?

Answer 1

a) Gravitational force is given by F = Gm₁m₂/r² 

b) same formula here, but you know F so you want to re-arrange the above into:

r² = Gm₁m₂/F

r = √(Gm₁m₂/F)