Question

The gravitational force between two masses separated by a distance is F. The magnitudes of two masses are doubled and distance between them is reduced to half of the initial distance. The gravitational force between them will be:

[A] F
[B] 2F
[C] 4F
[D] 16F​

Answer 1

F = G M m / R^2

F1 = G M m / R1^2

F2 = 4 G M m / R2^2

F2 / F1 = 4 * (R1 / R2)^2 = 4 / (1/2)^2 = 16

F2 = 16 F1