A loudspeaker emits a steady sound of frequency 250 Hz in air. The speed of sound in air is 340 m s−1.
(i) Calculate the wavelength of the sound in air.
(ii) How many complete sound waves pass a fixed point in 0.020 s?
(iii) When the same sound enters water, its speed becomes 1500 m s−1 while its frequency remains unchanged. Determine the wavelength of the sound in water.