Final answer:
Crests and troughs are two characteristics of transverse waves that are not found in longitudinal waves. Transverse waves exhibit medium disturbance perpendicular to wave direction, resulting in crests and troughs, while longitudinal waves show parallel medium displacement, seen as compressions and rarefactions.
Step-by-step explanation:
The characteristics that distinguish transverse waves from longitudinal waves are crests and troughs, as well as the manner in which they propagate through a medium. In a transverse wave, the medium's disturbance is perpendicular to the direction of wave propagation, resulting in the formation of crests (the highest points) and troughs (the lowest points). This is not found in longitudinal waves, where the medium's particles vibrate parallel to the direction of wave propagation, creating compressions and rarefactions instead.
Both types of waves have amplitude and wavelength; however, they manifest differently within the wave structure. The amplitude of a transverse wave is measured from the rest position to the crest or trough, while the wavelength is the distance from one crest to the next. In contrast, the amplitude of a longitudinal wave is related to the density of the compressions, and the wavelength is the distance between successive compressions or rarefactions.