Evaluate the speed of sound at 45 ∘C. (Take the speed of sound in dry still air at 0 ∘C to be 330 m/s.)
How long will sound take to travel in (a) an iron rail and (b) air, both 3-3 km in length ? Take speed of sound in air to be 330 m s−1 and in iron to be 5280 m s−1.