Question

Explain how sound is produced by your school bell? Why are sound waves called mechanical waves?

Answer 1

Hint:Whenever sound waves travel through any medium, the particles of the medium undergo compression and rarefaction. When the particles of the medium come closer then it is known as compression. On the other hand, when the particles move apart from their normal position it is known as rarefaction.

Complete step-By-Step answer:
Step I:
The waves that need a material medium like solids, liquids or gas to propagate are known as sound waves. Since sound waves also need a material medium to propagate so they are known as mechanical waves. Sound waves have five characteristics- wavelength, velocity, time period, frequency and the amplitude.
Step II:
The school bell usually consists of a hammer and gong connected to an external source of current. When the school bell is struck with a hammer, the hammer hits the gong again and again that causes compressions and rarefactions in the air. These vibrations travel in the air in the form it starts vibrating and as a result sound is produced in the bell.

Note:It is important to remember that a sound is a type of disturbance that is carried from one location to another that occurs when the particles of the medium vibrate back and forth along their mean position. These waves are perceived by the brain when the eardrum of the observer also vibrates as a result of the surrounding air. Sound waves are also known as elastic waves as they are produced in an elastic medium and these are governed by Newton’s laws of motion.