Speed of Water Waves
- When straight waves pass from deep to shallow water, their
- wave-length becomes shorter
- speed decreases
- frequency remain unchanged
- This can be illustrated by placing a piece of rectangular Perspex of suitable thickness in the tank to reduce the local water depth.
- The figure below shows the wavefront diagram of the wave formed.
- We can see that the wavelength above the Perspex is shallower.
- The relationship between the speed and wavelength of the wave in the deep and shallow region is given by the formula below. vd = speed of wave in the deep regionλd = speed of wave in the deep regionvs = speed of wave in the shallow regionλs = speed of wave in the shallow region