For a fixed distance D between a source and a listener, let the speeds of sound in two different media be v1 and v2.
(a) Derive an expression showing that the ratio of the times taken for the sound to cover the distance in the two media is t2t1=v1v2.
(b) Using D=1km, calculate the time taken for sound to travel the distance through (i) air (v=340m/s), (ii) water (v=1500m/s) and (iii) steel (v=5000m/s).
(c) By how much time does sound travelling through steel reach the listener earlier than sound travelling through air for the same distance? Comment on the practical significance of this difference.