The wavelength of a longitudinal wave could also be measured from the centre of a rarefaction to the centre of the next rarefaction. Frequency – the number of vibrations in one second.

The unit of frequency is hertz (Hz)., wavelength close wavelength The length of a single wave, measured from one wave peak to the next. and the speed of water waves.

Sunday Times News: Sound is propagated in the form of longitudinal waves. When sound travels from one medium to another, both its velocity and wavelength undergo changes ...