Question

Rarefaction and compression of longitudinal waves

Answer 1

However instead of crests and troughs, longitudinal waves have compressions and rarefactions. A compression is a region in a longitudinal wave where the particles are closest together. A rarefaction is a region in a longitudinal wave where the particles are furthest apart.

Answer 2

a comperssion is that part of longitudinal wave in which particles of the medium are closer to each other. while in rarefaction is that part in which the particles of medium are away from each other...