The force applied to change the momentum of an object results in a force equal in , but opposite in direction to the object that is applying the force. This is an application of Newton's law, resulting in conservation of of the system consisting of both objects.

The statement you provided is an application of Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. This law results in the conservation of momentum of the system consisting of both objects.

Here's a step-by-step explanation:

1. An object applies a force to another object.
2. According to Newton's Third Law, the second object will apply a force that is equal in magnitude but opposite in direction to the first object.
3. This interaction does not change the total momentum of the two-object system. The momentum lost by the first object is gained by the second object, and vice versa.
4. Therefore, the total momentum of the system is conserved.

This principle of conservation of momentum is fundamental in the study of physics and is used to analyze the motion of objects in a variety of scenarios, from collisions to rocket propulsion.