Define- compression and rarefaction.

In the context of waves, compression and rarefaction are two fundamental concepts associated with the behavior of waves, particularly in longitudinal waves such as sound waves.

Compression refers to the region of a wave where the particles or medium through which the wave is traveling are densely packed or compressed. In this region, the particles are closer together than their equilibrium or rest position. The compression represents the high-pressure region of the wave.

Rarefaction, on the other hand, is the region of a wave where the particles or medium are spread out or rarefied. In this region, the particles are farther apart than their equilibrium position. The rarefaction represents the low-pressure region of the wave.

When a longitudinal wave, such as a sound wave, propagates through a medium, it causes a series of compressions and rarefactions. As the wave travels, it creates alternating regions of high pressure (compression) and low pressure (rarefaction) within the medium. These regions of compression and rarefaction continue to propagate through the medium, carrying the energy of the wave with them.

In summary, compression refers to the region of a wave where particles are densely packed, while rarefaction refers to the region where particles are spread out. These alternating regions of high and low pressure create the characteristic pattern of a longitudinal wave as it travels through a medium.