Phenomena of Wave - Reflection and Refraction

Reflection of Straight And Circular Wave

From Deep to Shallower Region

When plane waves move from deep to shallow water, their wavelength become shorter and the velocity decreases.

The frequency of the wave 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.

Refraction of Water Wave

The change in wavelength and speed causes a change the waves direction when they cross the boundary. In other words, refraction occurs.

Refraction - Deeper to Shallower Region

When water waves are propagating from deeper region to a shallower region, the wave will be refracted approaching the normal.

Refraction - Shallower to Deeper Region

When water waves are propagating from shallower region to a deeper region, the wave will be refracted away from the normal.

Some Other Pattern of Refraction

Natural Phenomenon Involves Refraction

The effect of refraction causes seaside near to a cape is stony while sea near to a bay is sandy.

• At the middle of the sea, the wavefront is a linear line.
• When waves move close to the coast line, the wavefronts start to curve and follow the topography of the coast line.
• At the bay, the energy of the wave spread to a wider area, and cause the amplitude to reduce.
• At the cape, the energy of the wave is converged to a smaller area, therefore the amplitude of the wave increases.