Final answer:
The change in momentum when an object is suddenly stopped is determined by its mass and the change in velocity, in accordance with Newton's second law of motion and the principle of conservation of momentum.
Step-by-step explanation:
When something is suddenly stopped, the change in momentum is determined only by its mass and the change in velocity. Momentum, defined as a product of an object's mass and its velocity, plays a crucial role in physical phenomena regarding motion. According to Newton's second law of motion, a force—the action of an outside influence—leads to the change in momentum of an object. The applied force changes the momentum in the direction of the force, thereby effecting changes in either speed, direction, or both of the object.
Therefore, if an object is brought to a halt abruptly, such as in a collision, its initial momentum (mass times initial velocity) will undergo a change. This change in momentum is equal to the mass times the change in velocity, which essentially means the final velocity post-collision minus the initial velocity just before the collision. This is a direct application of the conservation of momentum principle, which states that when the net external force is zero, the total momentum of a system remains constant.