Two small objects,with masses m and M,are originally a distance r apart,and the gravitational force on each one has magnitude F.The second object has its mass changed to 2M,and the distance is changed to r/4.What is the magnitude of the new gravitational force?
A)F/32
B)F/16
C)16F
D)32F
E)2F

Question

Quizplus · Accepted Answer

The gravitational force is given by Newton's law of gravitation: F = G(m1*m2)/r^2. Initially, F = G(m*M)/r^2. When the second mass is changed to 2M and the distance to r/4, the new force F' = G(m*2M)/(r/4)^2 = G(m*2M)/(r^2/16) = 32G(m*M)/r^2 = 32F.

Two Small Objects,with Masses M and M,are Originally a Distance