Question

What happened if we not conserve momentum

Answer 1

If law of conservation of momentum was wrong,then momentum can be created of destroyed.In simple words,this means that

According to conservation of momentum,when a ball of velovity V hits another ball,the first ball stops and the second ball attains a velocity of V.

But if the conservation of momentum was wrong,then when the ball hits the second ball,then either the ball stops and 2nd ball don't move(here, momentum is destroyed) or the second ball travels with a higher velocity than V(here momentum is created.).