crest

(noun)

The ridge or top of a wave.

Related Terms

Examples of crest in the following topics:

  • Conditions for Wave Interference: Reflection due to Phase Change

    • If a crest of one wave meets a crest of another wave of the same frequency at the same point, then the magnitude of the displacement is the sum of the individual magnitudes.
    • Destructive interference occurs when the crest of one wave meets a trough of another wave.
    • When light is reflected off a medium with a higher index of refraction, crests get reflected as troughs and troughs get reflected as crests.

  • Wavelength, Freqency in Relation to Speed

    • The amplitude is half of the distance measured from crest to trough.
    • We also observe the wavelength, which is the spatial period of the wave (e.g. from crest to crest or trough to trough).
    • The frequency of a wave is the number of cycles per unit time -- one can think of it as the number of crests which pass a fixed point per unit time .
    • For such a component, any given phase of the wave (for example, the crest) will appear to travel at the phase velocity.

  • Transverse Waves

    • The wavelength spans crest to crest while the amplitude is 1/2 the total distance from crest to trough.
    • The wavelength is the distance between adjacent crests.
    • The amplitude is the 1/2 the distance from crest to trough.

  • Doppler Effect

    • The time between the arrival for two crests of the wave in the unprimed frame is given by,

  • Young's Double Slit Experiment

    • Constructive wave interference occurs when waves interfere with each other crest-to-crest (peak-to-peak) or trough-to-trough (valley-to-valley) and the waves are exactly in phase with each other.
    • Destructive wave interference occurs when waves interfere with each other crest-to-trough (peak-to-valley) and are exactly out of phase with each other.
    • The waves all start out in phase (matching crest-to-crest), but depending on the distance of the point on the wall from the slit, they could be in phase at that point and interfere constructively, or they could end up out of phase and interfere with each other destructively.

  • Superposition and Interference

    • When two identical waves arrive at the same point exactly in phase the crests of the two waves are precisely aligned, as are the troughs .
    • If two identical waves that arrive exactly out of phase—that is, precisely aligned crest to trough—they may produce pure destructive interference.

  • Water Waves

    • Both air pressure differences between the upwind and the lee side of a wave crest, as well as friction on the water surface by the wind (making the water to go into the shear stress), contribute to the growth of the waves.
    • As the wave amplitude (height) increases, the particle paths no longer form closed orbits; rather, after the passage of each crest, particles are displaced slightly from their previous positions, a phenomenon known as Stokes drift.

  • The Speed of a Wave on a String

    • The peak is the crest, or top point of the wave and the trough is the valley or bottom point of the wave.

  • Reflections

    • The peak is the crest, or top point of the wave and the trough is the valley or bottom point of the wave.