When sound waves propagate through different mediums, such as air, water, or solids, their speed can be affected. The speed of sound in a medium depends on the properties of that medium, primarily its density and elasticity.
In general, sound travels faster in denser and more elastic mediums. This means that sound waves typically travel faster in solids compared to liquids, and faster in liquids compared to gases. For example, the speed of sound in air at room temperature is approximately 343 meters per second, while in water it is around 1,484 meters per second, and in steel it can reach 5,960 meters per second.
When the medium changes, the speed of sound changes as well. However, the frequency and wavelength of the sound wave remain unaffected. The frequency of a sound wave represents the number of oscillations (or cycles) of the wave per second and determines the pitch of the sound. The wavelength is the distance between two consecutive points in a sound wave that are in phase (e.g., two crests or two troughs). The wavelength, together with the speed of sound, determines the frequency of the wave through the equation:
Frequency = Speed of Sound / Wavelength
Since the speed of sound changes when the medium changes, but the frequency remains constant, the wavelength must also change to maintain the relationship. When sound waves pass from one medium to another, they experience a change in speed, but their frequency remains the same. As a result, the wavelength of the sound wave adjusts to accommodate the new speed.
This phenomenon is known as the wavelength/frequency relationship. When a sound wave enters a new medium, its wavelength adjusts according to the ratio of the speeds of sound in the two mediums. If the new medium has a higher speed of sound, the wavelength increases, and if the new medium has a lower speed of sound, the wavelength decreases. This adjustment allows the sound wave to maintain a constant frequency while traveling through different mediums.