Question: A space probe is launched from the Earth, headed for deep space. At a distance of 20,000 km from the Earth's center, the gravitational force on it is 1000 N.
Part A: What is the size of the force when it is at each of the following distances from the Earth's center?
(a) 40,000 km;
(b) 60,000 km;
(c) 300,000 km;
Show how you get the answer, so that I can better understand how to do it.