Marine biologists study the propagation of low-frequency sound (40Hz) used by blue whales for communication. Near the ocean surface, where the water temperature is 25∘C, the speed of sound is 1530m/s. The same sound wave then travels into an underlying colder layer at 5∘C where the speed of sound is 1435m/s. After crossing the thermocline, the wave eventually emerges into air where the speed of sound is 343m/s. Assume no reflections occur at the boundaries.
(a) Determine the wavelength of the sound wave in the warm surface layer.
(b) Determine the wavelength of the sound wave in the colder layer.
(c) A member of the research team claims that the whales would perceive a lower pitch once the wave enters the colder layer. Evaluate this claim and justify your reasoning based on wave properties.
(d) Calculate the wavelength of the sound wave in air after it leaves the water, and state whether the frequency of the wave in air differs from that in water. Explain your answer.