Question

A sphere of mass 40kg is attracted by a sphere of mass 80 kg by a force of 2.5 ×10^-6 N, when their centres are 300 mm upward. Find the value of G.

Answer 1

F = Gm1m2 / d^2

G = Fd^2 / m1m2

G = 2.5 x 10^-6 x (300 x 10^-3)^2 / 40 x 80

G = 0.225 x 10^-6 / 3200

G = 7.031 x 10^-11