Is force needed to keep a moving body in motion?
No , it is not necessary to apply force to keep the body moving as such. One a body is set in motion, Unless there is any external force it will continue to move with present state of motion.
A force is needed to: (a) change the state of motion or state of rest of the body (b) keep the body in motion (c) keep the body stationary (d) keep the velocity of body constant.
The force required to keep a body in uniform circular motion is