A railway worker strikes one end of a long steel rail with a hammer to signal a colleague stationed 1530m away along the track. The colleague hears two separate sounds, one arriving through the metal rail and the other arriving through the air.
Use the following data at 20∘C:
Speed of sound in steel =5100m/s
Speed of sound in air =343m/s
(a) Calculate the time taken for the signal to reach the colleague through (i) the steel rail and (ii) the air.
(b) Determine the time interval between the arrival of the two sounds.
(c) Provide a comprehensive explanation, in about 80–100 words, for the large difference in arrival times. In your answer, clearly link your reasoning to differences in (i) particle arrangement, (ii) density, and (iii) elasticity of the two media.