Total momentum in an isolated system does not change. the law of physics that states that the linear momentum does not change unless an external force acts upon it.
The law of conservation of momentum explains that momentum is neither lost or gained. "when two bodies collide with one another, the total energy remains constant. That means that the total amount of momentum doesn't change.
In a collision or Newton's Cradle. (5 balls hanging on a string, when you move one to hit the other balls, there is a reaction ) . Recoil
Momentum is the concept that links the action of a force and the change of speed it produces. It accounts for the fact that a force will produce a large acceleration in a small mass but a small acceleration in a large mass. If this law was not universal, then the outcomes of identical interactions would vary,contrary to the basic tenets of physics.
Total Momentum After Collision = Total Momentum Before Collision
: m1u1 + m2u2 = m1v1 + m2v2 ----( 1)
Elastic and Inelastic Collisions: ΔK.E. = (Total K.E.)after collision - (Total K.E.)before collision
: 1/2 (m1u1)^2 + 1/2 (m2u2) ^2 = 1/2(m1v1)^2 + 1/2 (m2v2) ^2 ----( 2)
Combined equation 1 & 2 to form a new formula .
TRY TO COMBINE THEM TO FORM A NEW AND USEFUL FORMULA :)