Newton€™s Law of Gravitation says that the magnitude F of the force exerted by a body of mass m on a body of mass M is where G is the gravitational constant and is the distance between the bodies.

(a) Find df/dr and explain its meaning. What does the minus sign indicate?
(b) Suppose it is known that Earth attracts an object with a force that decreases at the rate of 2 N/km when r = 20,000 km. How fast does this force change when r = 10,000 km?

Transcribed Image Text:

GmM F-