The law of conservation of momentum states that, if left alone, what happens to the total momentum of two interacting objects that make up a system?

it breaks and dirupture other materials and other sencews from the bottom

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.