What is defined as an elastic collision?

• A. A collision where total momentum is conserved
• B. A collision where kinetic energy is lost
• C. A collision where kinetic energy is conserved
• D. A collision that does not involve any objects

Answer: (C)

An elastic collision is characterized by the conservation of kinetic energy in addition to the conservation of momentum. In this type of collision, when two objects collide and then separate, the total kinetic energy of the system before the collision is equal to the total kinetic energy of the system after the collision. This means that the individual speeds and masses of the colliding bodies will interact in such a way that energy is neither lost nor transformed into other forms, such as heat or sound.

The conservation of kinetic energy is a fundamental property that distinguishes elastic collisions from inelastic collisions, where total momentum is still conserved, but some kinetic energy is transformed into other forms, resulting in a loss of kinetic energy in the system. Thus, a collision that maintains the total kinetic energy before and after the event fits the definition of being elastic.