Question

You can also see the transfer of energy in an arrangement of children standing in a row almost touching each other. Now, give a push to the child in front. You will see that almost every child moves at his or her position, or the disturbance is pushed on. A wave is a means of carrying energy from one place to another. Light rays behave like waves-they carry energy from one place to another. The sun’s rays carry heat energy and light energy from the sun to the earth. Heat rays carry heat energy from an electric heater wire to a cold room. Similarly, sound waves carry sound energy from a source to your eardrums.

The above activities lead us to the definition of wave motion. It is defined as the process by which a disturbance at one point in a medium is propagated to another point, more remote from the source with no net transport of the material of the medium itself. 

Answer 1

This activity demonstrates wave motion. The children represent particles of a medium. Each child moves about his or her position and passes the disturbance to the next child. Thus, energy is transferred without any net transfer of matter.

Similarly, sound waves are mechanical longitudinal waves that carry sound energy from a vibrating source to the ear through a material medium.