Waves GapFill

Waves are the repeated motion of particles (or fields) around a point, that carry energy from one place to another.
Frequency (f) and period (T) of waves are related by the equation  f = 1/T²f = 1/Tf = T/2f = T².
Wave speed (v), frequency (f) and wavelength (λ) are related by the equation  v = fλv = f/λv = f²λv = fλ².

When a wave meets a boundary between two materials, it can be absorbed, transmitted or reflected. Whether a wave is absorbed, transmitted or reflected can vary with  the materials comprising the boundarythe wave speedits wavelength and the materials comprising the boundaryits speed in air and the angle of incidence.  A reflected wave  does not pass through the boundary, and instead travels back into the medium it was originally instops travelling once it reaches the boundarypasses through the boundary unchangedchanges direction after passing through the boundary.

The frequency generally remains unchanged when waves are reflected or transmitted. Where waves are transmitted at a boundary, the speed at which the wave can travel will be different in different mediums. If the wave speed changes but the frequency remains the same, the  amplitudewavelengthwaveperiod will be different in the new medium. This usually results in a change of  amplitudemagnituderefractiondirection of the wave. This change of direction is known as  transmissionreflectiondiffractionrefraction.

Earthquakes produce  magma wavesterrestrial wavesgeographic wavesseismic waves, which travel through Earth's crust and mantle, and, when detected, can tell us information about where the earthquake originated and the composition of Earth.
Imaging techniques using sound measure  the intensity of the wavethe wavelength of the wavethe change in frequency of the wavethe time taken between a wave being emitted and detected to determine the distance to the reflecting object or surface