The gravitational force of a star on an orbiting planet 1' is F1. Planet 2, which is twice as massive as planet 1
and orbits at four times larger distance from the star,
experiences gravitational force F2
What is the ratio f2/f1? You can ignore the gravitational force between the two plane

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy.work depends on the square of the change in potential energy.work is equal to the negative of the change in kinetic energy.work is equal to the square of the change in kinetic energy