Question

A- trough or Crest

Answer 1

Answer:

A- Crest.

B- Wavelength.

C- Equilibrium.

D- Trough.

E- Amplitude.

Explanation:

1. A crest is the point on a wave of maximum value of upward displacement within a cycle.  
2. Wavelength is the distance between two identical adjacent points in a wave.
3. Equilibrium is a state of balance between opposing forces; a state of balance in which opposing forces cancel one another.
4. A trough is just the opposite of a crest, so it is the minimum(downward displacement) or lowest point of a wave in a cycle.
5. Amplitude of a wave is the maximum distance or displacement moved by a point on a vibrating body or wave. Amplitude of a wave is directly proportional(∝) to the amplitude of the vibrating object(source).

Result: Crest, wavelength, equilibrium, trough and amplitude is the correct answer.