Question

define momentum and prove the law of conservation of momentum

Answer 1

the quantity of motion in a body depends on the mass and velocity of the body, this gives us another term known as momentum.
The law of momentum conservation can be stated as follows for a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That momentum to the object 1 is equal to the momentum gained by object 2.

Answer 2

Momentum is defined as the product of mass ,m of the body and it’s velocity,v . It is a vector quantity. It’s SI Unit is kg m/s . Equation: p =mv
Law of conservation of momentum: sum of momenta of two objects before collision is equal to the sum of momenta after collision provided there is no external unbalanced force acting on it .
Hope it helps !