(a) The following four media are kept at the same room temperature of 25∘C:
1. A copper rod
2. Distilled water
3. Dry air
4. Moist air having 80\% relative humidity
Arrange the four media in the decreasing order of the speed of sound through them.
(b) Give a detailed explanation for the order you have written, clearly referring to the roles of (i) density of the medium and (ii) elasticity of the medium. State two separate reasons to justify why sound travels faster in moist air than in dry air even though both are at the same temperature.