Refraction of Sound Waves
Refraction of Sound Waves :- Refraction of sound waves refers to the bending of sound waves as they pass from one medium into another, where the speed of sound differs. This bending occurs due to the change in the speed of sound between the two mediums, causing the direction of the sound wave to change. The degree of bending depends on the angle of incidence, the difference in the speed of sound between the two mediums, and the density or temperature gradients present at the boundary.
Denser and Rarer Medium
(Refraction of Sound Waves)
A denser medium refers to a material or substance in which sound travels at a slower speed, while a rarer medium refers to a material or substance in which sound travels at a faster speed. It is the speed of wave which decides whether the medium is denser or rarer for that particular wave, i.e.,
Although the concepts of denser and rarer mediums apply to both sound waves and electromagnetic waves but remember that if a medium is denser for one type of wave then at the same time the same medium can be rarer for the other type of wave. For example air is considered a rarer medium compared to water for light (electromagnetic wave) because light travels faster in air than water. At the same time air is considered a denser medium compared to water for sound waves because sound waves travels faster in water in comparison to air.
Notice that as the wavefronts cross the boundary the wavelength changes, but the frequency remains constant and also note that no phase change occur during refraction.
The laws of refraction and reflection remains the same, i.e., the wave bends towards the normal if it travels from rarer medium to denser medium and vice – versa. Snell’s law relates the directions of the wave before and after it crosses the boundary between the two media. If v1 and v2 be the velocity of wave in first and second medium respectively then,
