Question

give reason : 1) why does a satellite move without needing a force to push it. 2) is any work done when you push your wall within your hands???

Answer 1

1)"Also,you don't have to keep pushing a satellite to keep it moving in space because there is no friction in space to cause things to slow down . .... A rocket work a by ejecting gas ,and because of Newton's Third law of motion, this produces an equal and opposite force in the direction the rocket travels."

2)No force is done by pushing wall with our hands

Answer 2

1)  Initially force applied to the satellite.Since there is no friction in space the            satellite remains in its state of motion until an external force is applied on it.

2)  No work is done when you push the wall with your hands because there is        no displacement.
 
                             Hope it helps...............