Conservation of linear momentum is consequence of which one of Newton's three laws?
But it's not very interesting if a single body continues with uniform velocity, at least as far as conservation of momentum goes.I think it is Newton's first law , because its statement itself says that until we apply an external force, a body continues to be in its original state of rest or of unifrm motion in straight line.
Yes, it's the third law that leads to conservation of momentum. Consider a collision between two bodies. Since they exert equal and opposite forces on each other for the same time, they produce equal and opposite changes in momentum in each other--thus the total momentum of the system remains unchanged.But one of my colleagues thinks that it is the third law, because action reaction forces are equal and the total external force on the system being zero , momentum is conserved.
I think it would be fair to say that it's a consequence of both first and third laws.