A wave’s amplitude is a measure of its maximum height from its rest position.
The wavelength (λ) of a wave can be shown in a diagram or it can be calculated using the formula: Wavelength = wave speed ÷ frequency.
The frequency of a wave is the number of waves that pass a certain point per second. It can be calculated using the waves time period, or speed and wavelength.
The time period of a wave is the time it takes a full wave cycle to pass a certain point. It is often calculated using the equation: Time Period = 1 ÷ frequency.
Wave speed is the distance travelled by a wave divided by the time it takes. The wave equation can be used to work out the speed of a wave.
When talking about phase difference (φ) we can be referring to two separate waves, or two particles in the same wave, and it tells us how far or behind one wave/ particle is from another. Phase difference is measured in radians or degrees and values can range from 0 to 2π or 0 to 360° with the value of π being half a wavelength. In the diagram particles 1 and 3 are in phase, but 1 and 2 are π radian out of phase with each other.