Final answer:
When a wave transitions between different media, refraction occurs, leading to a change in the wave's path, speed, and wavelength, along with variations in reflection and transmission dependent on media properties and boundary conditions.
Step-by-step explanation:
When a wave travels between media of different densities, the phenomenon of refraction occurs. Refraction is characterized by the bending of a wave as it passes from one medium to another with a different density. At the boundary, the wave changes its speed, direction, and wavelength. This adjustment in wave properties is due to variations in the acoustic impedance of the different media, which also results in different amounts of the wave being reflected and transmitted. In the case of light waves, for example, when light enters a denser medium, it typically slows down, causing the light to bend towards the normal line perpendicular to the surface at the point of incidence. Similarly, mechanical waves, such as those traveling along strings with different linear mass densities, demonstrate changes in phase and amplitude upon moving between different media.
The reflection and transmission of waves depend on several factors, including the boundary conditions, such as whether the boundary is fixed or free to move, and the difference in density and acoustic impedance between the two media. Greater differences in these properties typically lead to a higher degree of reflection and a lower degree of transmission.