Answer:
Please find the answer in the explanation
Step-by-step explanation:
When a Newton's Cradle with three marbles is pulled back and released, the mechanical energy is converted to potential elastic energy.
When a collision happens between the marbles causing a cycle of repeated motion, The elastic potential energy is converted to kinetic energy.
This transfer of energy will last for several cycles. If there is any energy lost, then the kinetic energy must have been converted to thermal energy or heat energy