Question

1. Sound wave comprises of a series of compressions and rarefactions.

a. What are compressions and rarefactions?

b. In which form of waves-longitudinal or transverse does sound travel?

Can sound travel in vacuum? Why?

Answer 1

Dear Student,
Sound is a vibration that is capable of being heard.
Sound propagates in a material by compression and rarefactions. When sound produced it vibrates the nearby air molecules. Air molecules are like small balls when sound travels through air it alternatively makes these balls pushed close together and then pulled away from each other. The area where they are together are called compressions and that area where they are away from each other are called rarefactions.
Sound travels by the means of longitudinal waves. It cannot travel through vaccum as there is nothing to push and pull there.