A rail track is struck with a hammer, producing a longitudinal wave that travels through the steel of the rail. The wavelength of this wave in the rail is measured to be 3.0m. The speed of sound in the rail steel is 5940ms−1 and the speed of sound in the surrounding air is 340ms−1.
(i) Determine the frequency of the vibration in the steel rail. Express your answer in kilo-hertz (kHz) correct to two significant figures.
(ii) Keeping the same source, find the wavelength of the sound that reaches an observer through the air. Give your answer in centimetres (cm).