1. Refraction: This is the most prominent effect. The wave bends, changing its direction. The angle of refraction depends on the angle of incidence (the angle at which the wave hits the boundary) and the relative speeds of the wave in the two media.
* Snell's Law: This law describes the relationship between the angles and speeds:
* n₁ sin θ₁ = n₂ sin θ₂
* where n₁ and n₂ are the refractive indices of the two media, and θ₁ and θ₂ are the angles of incidence and refraction respectively.
* Denser medium, slower speed: A denser medium generally slows down the wave. This means that the wave will bend towards the normal (the imaginary line perpendicular to the surface).
2. Partial Reflection: Not all of the wave energy enters the denser medium. Some of it is reflected back into the original medium at an angle equal to the angle of incidence.
* Amount of reflection: The amount of reflection depends on the difference in density between the two media. A greater difference in density leads to more reflection.
3. Change in Wavelength: The wavelength of the wave decreases as it enters the denser medium. This is because the wave's speed decreases, but its frequency remains constant.
4. Change in Amplitude: The amplitude of the wave may also change as it enters the denser medium. This is affected by factors like the amount of reflection and the energy absorption of the medium.
Examples:
* Light: When light enters water from air, it bends towards the normal because water is denser than air. This is why objects appear distorted when submerged in water.
* Sound: Sound waves travel slower in water than in air. When sound waves enter water from air at an angle, they bend towards the normal. This is why underwater sound detection systems can be used to locate objects.
Note: These effects are most pronounced when the angle of incidence is not zero (i.e., the wave hits the boundary at an angle). When the wave hits the boundary perpendicularly, there is no refraction, and the wave simply slows down.
