Describing Waves

Wavelength and Amplitude

reading the snapshot

Amplitude is the crest height and wavelength is the crest-to-crest distance, both read straight off the frozen wave picture.

Example

Amplitude is the crest height and wavelength is the crest-to-crest distance — both read straight off the frozen wave picture.

highlighted = computed this step

Amplitude: how far from the middle

The amplitude is the greatest displacement from the rest line — the height of a crest. Here the string rises 1 metre above the middle at each crest, so the amplitude is 1 metre.

A=1 mA = \hl{1}\ \text{m}
Amplitude is the crest heightThe wavy string with the height of a crest above the middle marked as the amplitude.Arest line

Wavelength: one full cycle in space

The wavelength is the distance over which the wave repeats — from one crest to the next. Reading the snapshot, successive crests are 3 metres apart, so the wavelength is 3 metres.

λ=3 m\lambda = \hl{3}\ \text{m}
Wavelength is crest to crestThe wavy string with the distance between two neighbouring crests marked as the wavelength.crestcrestone wavelength
waves Clean A = 1 m and wavelength = 3 m are read directly off the snapshot.