A factory siren produces a steady sound of frequency 850Hz.
(i) If the speed of sound in air is 340ms−1, calculate the wavelength of the sound waves in air.
(ii) A worker is standing 1020m from the siren. How many complete wavelengths of this sound are contained in the air column between the siren and the worker?
(iii) The sound enters a tube filled with helium where the speed of sound is 965ms−1. Keeping the frequency unchanged, calculate the wavelength of the sound waves inside the helium‐filled tube.