What is true about momentum in inelastic collisions according to Newton's laws?

In inelastic collisions, momentum is not conserved due to the nature of the interactions between colliding objects. Although individual momentum of each object before and after collision can change, the total momentum of an isolated system should theoretically remain constant, except in inelastic collisions where some kinetic energy is converted into other forms of energy, such as heat or sound.

In inelastic collisions, the objects involved stick together or deform, which results in a loss of kinetic energy. This energy transformation is crucial because even though the total momentum of the system (the vector sum of the momenta of all objects involved) may outwardly appear to change when observing the movement of the objects pre- and post-collision, it is the kinetic energy that drastically shifts. The unique aspect of inelastic collisions is that some momentum is "lost" to internal energy changes and may not contribute to the external measurable motion of the objects afterward.

Therefore, the characterization of momentum in inelastic collisions aligns with the idea that it is not conserved in the way energy conservation would suggest, where energy can convert from one form to another but still holds total energy constant in all processes.