Question
A body falls freely. Does the momentum of body remain conserved?
If not, does this example contradict the principle of conservation of momentum?
Solution
When a body is falling, it's momentum increases in the downward direction. But, this will not violate the law of conervation of momentum because there is external gravitational force acting on body, which increases the momentum of body.
But if we consider body and the earth as a system then total momentum of body and the earth remains constant because then gravitational force will be internal force.
