Conservation of Momentum – occurs in a closed system, where the momentum before an event is equal to the momentum after it
Closed System – nothing is allowed to enter or leave. There are no external forces acting on the system.
Elastic Collision – when the sum of all kinetic energies before an event is equal to the sum of all kinetic energies after
Inelastic Collision – when the sum of all kinetic energies before an event is not equal to the sum of all kinetic energies after
An elastic collision occurs when the relative speed before the collision is equal to the relative speed after the collision
