Answer to Question #303287 in Mechanics | Relativity for Amit

Question

A satellite of mass 200 kg is displaced by a distance of

2RE

from a point on the

Earth’s surface, where

RE

is the radius of the Earth. Calculate the work done on

the satellite by the force of gravitation. Take the values of the constants in your

calculation from the astrophysical data given in the course

Answer 1

$h=2R,$

$U=\frac 12 mg'h,$

$g'=g\frac{R^2}{(R+h)^2},$

$U=\frac{mgR^2\cdot 2R}{2(R+2R)^2}=\frac{mgR}{9}=1.4~GJ.$