Wave Speed & Phase Difference
Physics: AQA A Level, topic 3.1.2
Phase and Phase Difference
The phase of a wave is an important concept in physics. It can be expressed in fractions of a cycle or as an angle.
Definitions
- The phase of a wave describes how far through a cycle the wave is.
- Phase difference is a measure of the difference in where two waves are in their cycle.
Measurement
- Phase difference can be measured in angles or as a fraction of the wave cycle.
- A full cycle corresponds to one wavelength, λ, a half cycle as ½λ etc.
- Angles can be measured in degrees or radians.
- A full cycle is 360° (2π rad), a half cycle is 180° (π rad) etc.
Test yourself on Wave Speed & Phase Difference
If a wave has a frequency of 12 Hz and a wavelength of 3 m, how fast is it travelling?
If a wave has a frequency of 4 Hz and a wavelength of 8 m, how fast is it travelling?
If a wave has a frequency of 9 Hz and a wavelength of 2 m, how fast is it travelling?
If a wave has a speed of 9 m/s and a wavelength of 3 m, what is the frequency of the wave?
If a wave has a speed of 4 m/s and a wavelength of 8 m, what is the frequency of the wave?