Question

a satellite revolves round a planet in a circular orbit of radius r. if the gravitational force on the satellite by the planet is F newton, what is the work done by the planet on the satellite when the satellite covers half of orbit

Answer 1

Since, the gravitational force on the satellite by the planet is perpendicular at every instant of motion of the satellite, the displacement at any instant is thus perpendicular to the gravitational force. So, no work is done by the gravitational force when the satellite covers half of orbit.