A sound wave travels from air into water. Which of the following wave characteristics remains completely unchanged during this medium transition?

💡 Solution & Explanation

When a wave travels from one medium into another, its frequency remains strictly constant because it is determined solely by the vibrating source producing the wave. The speed and wavelength of sound change as it enters a denser medium like water due to different elastic and inertial properties. Amplitude may also vary due to reflection and absorption losses at the boundary interface. The product of frequency and wavelength equals the propagation speed in any given medium.