How does a wave behave at the boundary of two different mediums?

At the boundary of two different mediums, a wave can either be reflected, transmitted, or absorbed.

When a wave encounters a boundary between two different mediums, such as air and water, some of the wave's energy is reflected back into the original medium and some is transmitted into the new medium. The amount of reflection and transmission depends on the properties of the two mediums and the angle of incidence of the wave.

If the wave encounters a boundary at an angle, it will be refracted, or bent, as it enters the new medium. The amount of refraction depends on the angle of incidence and the difference in the speed of the wave in the two mediums.

If the wave encounters a boundary at a perpendicular angle, it will be neither refracted nor reflected, but will instead be absorbed by the new medium. This is because the energy of the wave is transferred to the particles of the new medium, causing them to vibrate and dissipate the energy as heat.

In summary, the behaviour of a wave at the boundary of two different mediums depends on the properties of the two mediums and the angle of incidence of the wave. The wave can be reflected, transmitted, refracted, or absorbed, and the amount of each depends on the specific circumstances of the interaction.