4.4.A—Describe whether an interaction between objects is elastic or inelastic

Describe whether an interaction between objects is elastic or inelastic.

• An elastic collision between objects is one in which the initial kinetic energy of the system is equal to the final kinetic energy of the system.
• In an elastic collision, the final kinetic energies of each of the objects within the system may be different from their initial kinetic energies.
• An inelastic collision between objects is one in which the total kinetic energy of the system decreases.
• In an inelastic collision, some of the initial kinetic energy is not restored to kinetic energy but is transformed by nonconservative forces into other forms of energy.
• In a perfectly inelastic collision, the objects stick together and move with the same velocity after the collision. TOPIC 5.1 Rotational Kinematics