Question

What is the work done by force of gravity on a satellite moving around the earth in the ircular orbit of radius 35000km?

Answer 1

work done by the gravity will be 0 ... because gravitational force is a conservative force... which depends on initial and final position of the particle....
or
we know that
work=fs.cos∅
f=mg which will act downward
and displacement will be perpendicular to the force... hence angle between force and displacement will be 90°
w= fscos90°
w=0 (because cos 90° = 0)