If the person standing near a railway line hears two distinct sounds of a train, then the sounds are - one travelling through steel and the another travelling through air.
Let the distance of train be d from the person.
speed of sound in air = 340 m/s
speed of sound in steel = 340 × 16 = 5440 m/s
time taken by sound travelling through steel to reach the person =
time taken by sound travelling through air to reach the person =
Distance of train is 725.33 m.