The acceleration due to gravity, g, is given by
where M is the mass of the earth, r is the distance from the center of the earth, and G is the universal gravitational constant.
(a) Show that when r changes by Δr, the change in the acceleration due to gravity, Δg, is given by
(b) What is the significance of the negative sign?
(c) What is the percent change in g when moving from sea level to the top of Pike's Peak (4.315 km)? Assume the radius of the earth is 6400 km.