Which best explains why the acoustics underwater affect the Doppler effect?

Sound waves can not transfer energy through water.

Sound waves can not travel through water.

The speed of sound is less in water than in air.

The speed of sound is greater in water than in air.

Answer:The speed of sound is greater in water than in air.

Explanation: The speed of a sound wave in a medium depends upon the density of the medium through which the sound is traveling. We know speed of a mechanical wave can be calculated as Frequency * Wavelength. Frequency does not change with the change of medium. It depends on the source frequency. But wavelength can be altered. As speed of sound is greater in water than in air and frequency remains the same, so wavelength should be increased to compensate the increase in speed of sound wave.