Q) Suppose two satellites are orbiting the Earth with the same orbital radius and the same period.However, one satellite is 20 times more massive than the other.This is possible, because. A) the gravitational force is inversely proportional to r^2. B) the gravitational force is proportional to mass. The answer is B. The explanation as follows:B says that the mass of a body increases, the force of gravity on that body increases proportionately. However, since F=ma, the net force on the satellite also increases proportionality with mass, and these two effects cancel each other out. I do not understand where did the F=ma come from and how does it cancel the force of gravity?