Railroad track and sound waves

[m.l.]

Homework Statement

People put their ears to a railroad track to get an early warning of an approaching train. why did this work.

Homework Equations

written response.

The Attempt at a Solution

Sound waves can travel a long way along an undisturbed metal rod?

 

[Kurdt]

The rod has to be disturbed for any sound to be carried along it. Apart from traveling a long way in the rail, what other property does sound have in the metal that is greater than in air that would be an advantage?

 

[nlightner]

This phenomenon is known as "railroad tracking." When a train approaches, the wheels create vibrations that travel through the track, causing the track to vibrate. This vibration then produces sound waves that can travel through the track and be detected by a person's ear when placed on the track. The sound waves act as an early warning system for an approaching train, allowing people to move out of the way and avoid potential accidents. This method is effective because sound travels faster and farther through solid materials, such as metal, compared to air. This is also why train conductors use their horns to signal their presence to others on the tracks. In summary, the ability of sound waves to travel through solid materials is the reason why placing one's ear on a railroad track can provide an early warning of an approaching train.