Answer:
Sound energy
Explanation:
The sound wave carries the energy from one particle to another particle. Sound wave is a longitudinal wave. In a longitudinal wave, there are rarefaction and compression. It can travel in solid, liquid and gas.
In the given problem, a swallow sitting on a fence sings a song for anyone who will listen. Sound waves travel from one particle to another in the air and in this way, sound energy will get transferred from the source (a swallow) to the listener. Sound waves need a medium to travel.
In the given system, the potential energy is stored due to the position of a swallow and kinetic energy is due to the motion of particle in the air.
