In a school experiment, a bell is rung continuously inside a long transparent tube. The bell vibrates at a constant frequency of 600Hz.
(a) Calculate the wavelength of the sound produced in air at 20∘C, where the speed of sound is 343m/s.
(b) The tube is then completely filled with carbon dioxide, in which the speed of sound is 270m/s. The bell continues to ring at the same frequency. Determine the wavelength of the sound in carbon dioxide.
(c) By what percentage has the wavelength changed on replacing air with carbon dioxide? Show all steps of your calculation.
(d) State, with reason, whether the pitch of the sound heard by an observer outside the tube changes when the gas inside the tube is replaced.