Speed of Waves

Speed of Water Waves

1. When straight waves pass from deep to shallow water, their
1. wave-length becomes shorter
2. speed decreases
3. frequency remain unchanged
2. This can be illustrated by placing a piece of rectangular Perspex of suitable thickness in the tank to reduce the local water depth.
   
   
3. The figure below shows the wavefront diagram of the wave formed.
   
   
4. We can see that the wavelength above the Perspex is shallower. 
5. The relationship between the speed and wavelength of the wave in the deep and shallow region is given by the formula below.
   
   v_d = speed of wave in the deep region
   λ_d = speed of wave in the deep region
   v_s = speed of wave in the shallow region
   λ_s = speed of wave in the shallow region