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In a time of one period, the movement of the wave is one wavelength. Therefore, one

must combine this information with the equation for speed. Consequently, one can say
that the speed of a wave is certainly the wavelength/period.

Speed = Wavelength/ Time Period

Also, the period refers to the reciprocal of the frequency. The substitution of the

expression 1/f can take place into the above equation for period. Therefore, the
rearrangement of the equation gives a new equation of the form:

Speed = Wavelength × Frequency

The above equation or formula is the waves equation. It gives the mathematical

relationship between speed of a wave and its wavelength and frequency. Therefore,
the equation or formula can be rewritten as

v = f × λ
where, v = speed of

f = frequency
λ = wavelength

Amplitude

The magnitude of disturbance in a medium on either side of the mean value is called
an amplitude (A).

As shown in the figure below, the unit of amplitude will be the density or pressure.
Distance between mean position and crest (maximum displacement).

Amplitude (A)