Question 919439
force of gravity between two objects is given by
F = (m1 * m2)G / d^2, where m1, m2 are the masses of the two objects, d is the distance between them, and G is force of gravity 32.2 feet per second ^2
we are given in the example
80 = (m1 * m2)G / 4000^2
(m1 * m2)G = 80 * 4000^2 = 1280000000
therefore
F = 1280000000 / 5000^2 = 51.2 pounds