* Total kinetic energy: This is the defining characteristic of an elastic collision. The total kinetic energy of the system before the collision is equal to the total kinetic energy after the collision.
* Total momentum: The total momentum of the system (the vector sum of the momenta of all objects involved) is conserved in all collisions, including elastic ones. This is a fundamental principle of physics.
Let me know if you would like more detail on either of these concepts!
