Crests and troughs: the top and bottom points reached by transverse waves.
Wavelength (λ) : the distance from one wave crest or trough to the next. The SI unit for the wavelength is the metre (m).
Amplitude: is the height of the wave crest or the depth of the trough from the middle, which is the position of the rope at rest, to its’ point.
Frequency: the number of wave crests passing a fixed point per second. The SI unit is the hertz (Hz). A wave passing a point every second is a frequency of 1Hz.
Period: the time taken to produce one complete wave. The SI unit is second(s).
Speed: distance travelled by one wave in a second. The SI unit is metres per second(m/s).
Wave front: a wave front is an imaginary line or surface, in the path of a wave motion, where all the displacements at any point have the same phase. A point source leads to circular wave fronts, at large distances from the source they are straight lines. A ray is a line that shows the direction of the wave and is perpendicular to the wave fronts.
For all waves there is a relationship between frequency, wavelength and velocity:
Velocity (v) = frequency (f) × wavelength (λ)
