If a sound travels from air to water then which quantity will remain unchanged? a) velocity b) wavelength c) frequency d) amplitude
Just as with light the velocity is the product of frequency times wavelength. In the case of a sound of frequency f generated by a source S, the frequency does not change going from air to water. The speed of sound changes from 331 m/sec in air to 1480 m/sec in water. So the wavelength = v/f increases about 4.5 times in water compared to air. At 100 Hz frequency the wavelength in air is 11.3 ft. and in water its about 48 ft.