Question

A sound wave generated from a tuning fork of single frequency travels from air (with speed of sound 340 m/s) into rock (with speed of sound 1500 m/s). Which statement is true about the wavelength and frequency of the sound as it passes from air to rock?

A) The frequency of the sound increases and the wavelength increases.

B) The frequency of the sound increases and the wavelength is unchanged.

C) The frequency of the sound is unchanged and the wavelength is decreased.

D) The frequency of the sound is unchanged and the wavelength is increased.

E) The frequency of the sound decreases and the wavelength is increased.

Answer 1

The correct option is: (D) The frequency of the sound is unchanged and the wavelength is increased.

Explanation:

When traveling between mediums, sound behaves opposite from light. As given in the problem the sound travels faster in the denser rock. When the sound speeds up, the wavelength increases and the frequency stays the same.