question at position 1 determine which one of the following statements is false: determine which one of the following statements is false: momentum of the system is constant for elastic collisions, but momentum of the system is lost during inelastic collisions. elastic collisions are those for which kinetic energy is constant before and after the collision; inelastic collisions are those for which some or all of the kinetic energy is lost during the collision. when analyzing a collision question, it is sometimes necessary to use both conservation of momentum and conservation of energy to model the system and predict the outcome. when a large truck collides with a small car, we typically observe the small car taking very significant structural damage, whereas the truck typically has very little damage, yet both the car and truck experience the same magnitude of force during the collision time as indicated by newton's 3rd law. in both conservation of energy and momentum analysis methods, we must first define our system and our surroundings, then identify the initial and final states of the system, consider if any net external forces act on the system, construct a mathematical equation comparing the initial and final states as well as the effect of any external forces, and proceed with our solution.