Question

How long will sound take to travel in (a) and iron rail and (b) air, both 3.3 km in length? Take speed of sound in air to be 330 m/s and in iron to be 5280 m/s.

Answer 1

(a) Length of iron rail (D) = 3.3 km = 3300 m

Speed of sound in iron (V) = 5280 m/s

Time taken by sound to travel in iron rod (t) = D/V

Or, t = (3300 / 5280) s = 0.625 s

(b) Length of iron rail (D) = 3.3 km = 3300 m

Speed of sound in air (V) = 330 m/s

Time taken by sound to travel in iron rod (t) = D/V

Or, t = (3300/330) s = 10 s