Answer:
crest and trough
Step-by-step explanation:
A wave is characterized by some elements, which are:
- Crests: The highest points of a wave are the crests.
- Valley: The lowest points of a wave form the valleys.
- Amplitude: The distance from the position of the resting wave to a crest or a valley.
- Wavelength: is the distance between two successive ridges or two successive valleys.
- Period: This is the time taken to produce a complete oscillation (one cycle), that is, the time when the source generates one up and one down cycle.
- Frequency: number of complete oscillations (cycles) generated per unit of time (minutes, seconds, etc.)