Howdy! can be replied to with just a nod and a smile. It simply means Hi! in Texan - not How are you doing?. Or you might reply, Hey Y'all Doon? if you want to engage in proper Texan interactions. Replying in proper English, well pronounced, with each syllable clearly spoken, is HIGHLY discouraged.
The crest of a wave is the point of maximum positive displacement, or upward movement, away from equilibrium, or an undisturbed state. The opposite of crest is trough, which is the point of the greatest negative, downward displacement.
6. crest or crest line 7. trough or trough line 8. wavelength 9. The period is the time it takes successive crests or troughs to pass a stationary point 10. wave height 11. The magnitude of the velocity or speed is wavelength divided by time; hence, the velocity is 40 meters/8 seconds or 5 meters/sec. 12.