Question
A sphere of mass 40 kg is attracted by a second sphere of mass 60 kg with a force equal to 4 mgf. If G = 6 x 10-11 N m2 kg-2, calculate the distance between them. Acceleration due to gravity = 10 m/s2
Solution
We have,
Mass, m1 = 40 kg ; m2 = 60 kg
Also, F = 4 mgf = 4 x 10-6 x 10
= 4 x 10-5 N
G = 6 x 10-11 N m2 kg-2
Distance between the masses, r = ?
Gravitational force is given by, F = 
This implies,
r = 
