# physics

posted by
**becky** on
.

A satellite has a mass of 100 kg and is in an orbit at 2.00*10^6 m above the surface of the Earth (a) what is the potential enegry of the satellite at this location?(b) what is the magnitude of the gavitational forece on the satellite?

a) Since the weight drops somewhat as a result of the inverse square law, you have to use the relation

PE = -GM/r

where G is the universal gravitational constant and M is the mass of the Earth. PE can also be written

PE = -gR^2/r where g is the acceleration of gravity at the earth's surface.

Therefore PE at altitude h, relative to the value at the earth's surface, is

- g R^2 [1/(R+h) - 1/R]

(b) Use the inverse square law and the ratio of the earth's radius to the height of the satellite above the center of the earth.