A 200 kg alien is wandering through space around his home planet. The alien measures the gravitaitonal force from the planet to be 700 N. While going through space, the alien sees some giant space slugs in the distance. He decides to journey there and upon arrival, he snacks on them. As a result, the distance between the alien and the center of the planet increases by a factor of 4 and his mass increases to 800 kg.
What is the gravitational force on the alien after eating the giant space slugs?
Foriginal = 700 = G m M / r^2
700 = G 200 M / R^2 = 200 G M / R^2
so G M/R^2 = 7/2
then later
F = G 800 M/ (4R)^2 = (800/16) G M/R^2
= (800/16) * (7/2) Newtons