Question

Please include as detailed an explanation as possible with equations and concepts written out.

1. In old cowboy movies, you have probably seen someone place his ear on railroad rails to tell if a train is coming. Prove why is this done, and how does it work? Explain your reasoning.
2. There is a biological reason why a church does not need an organ pipe longer than 4.0 m. Prove the reason that this is true.
3. In many churches there are much longer pipes. What is their effect? Explain your reasoning.
4. When a gong is sounded, it produces sound waves in air. If the same gong were struck in a vacuum, would it continue to vibrate for less time, for the same amount of time, or for more time than it does when struck in the same way in air? Explain your reasoning.

Thank you :)

Answer 1

A.) Sound wave can travel faster in railway track in comparison to air hence one can listen sound by placing ear on railway track even when train is very far and not visible

B.) because as length of of organ pipe increase than it's fundamental frequency decreases and if its length is longer than 4 m than fundamental frequency produced is less than 20 Hz which cant be listen  by human ear

C.) Since it is vibrating in vacuum where there is not any damping medium hence it will continue to vibrate because no energy is lost or transferred but it will not produce any sound because sound is a mechanical wave and it need a medium to propagate