What occurs when sound waves enter a medium of lower density?

When sound waves enter a medium of lower density, the phenomenon observed is a decrease in speed. This is because sound waves travel more quickly in denser mediums due to the closer proximity of molecules, which facilitates more efficient energy transfer.

In lower density media, the molecules are spaced further apart, which means that the transmission of sound energy encounters greater resistance and, consequently, the propagation speed of the sound waves diminishes. This effect is influenced heavily by the physical properties of the mediums involved, such as their elasticity and temperature, in which density plays a critical role.

Understanding this concept is essential in applications involving acoustics, such as sonar systems, audio engineering, and various fields of physics and engineering, as the speed of sound directly affects how sound is utilized in those domains.