Final answer:
To predict the change in final momentum compared to initial momentum, the law of conservation of momentum must be considered. If no external forces act on the system, the initial and final momentum would be the same. If there are external forces, the final momentum may differ due to their impact.
Step-by-step explanation:
To predict how the final momentum of a system will compare to the initial momentum that is measured, you need to consider the law of conservation of momentum. According to this law, the total momentum before the event should be equal to the total momentum after the event in an isolated system. So, if no external forces act on the system, the initial and final momentum would be the same.
For example, let's say you have two objects of masses m1 and m2 initially at rest. If they collide elastically, meaning there is no loss of kinetic energy, the final momentum of the system would be the same as the initial momentum, which is zero. However, if the collision is completely inelastic, meaning the objects stick together after the collision, the final momentum would be the sum of the initial momenta of the two objects.
It's important to note that if there are external forces acting on the system, such as friction or a net force, the final momentum may differ from the initial momentum due to the impact of these external forces.