Why does sound travel faster in helium that is lighter than air but also travels faster in water that is more dense than air?
In: Physics
I am confident that my research into the op subject matter is factual. That I lack a complete understanding of the subject is not pertinent to the discussion.
Furthermore there was no ‘guess work’ involved.
Please refer to the following links.
[speed of sound through helium ](http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/souspe.html#:~:text=Sound%20Speed%20in%20Helium.%20The%20speed%20of%20sound,is%20so%20much%20less%20than%20that%20of%20air.)
Speed of sound through water.
[speed of sound through water](https://hypertextbook.com/facts/2000/NickyDu.shtml#:~:text=The%20speed%20of%20sound%20can%20also%20be%20affected,water%20at%20room%20temperatures%20%2820%20to%2025%20%C2%B0C%29.)
[thermal conductivity of gases](https://www.engineersedge.com/heat_transfer/thermal-conductivity-gases.htm#:~:text=%20%20%20Gas%20%20%20Temperature%20%C2%B0C,x%2010%20-6%20%2019%20more%20rows%20)
[can sound generate heat? ](https://wtamu.edu/~cbaird/sq/mobile/2015/11/05/can-sound-waves-generate-heat/)
Following the above links we can see that temperature and pressure both affect the ability of sound to travel through a given medium. In our case air/helium/water.
Since sound waves are a form of mechanical energy they are governed by the laws of thermal dynamics.
[fundamentals of sound](https://phys.libretexts.org/Courses/University_of_California_Davis/UCD%3A_Physics_9B__Waves_Sound_Optics_Thermodynamics_and_Fluids/02%3A_Sound/2.01%3A_Fundamentals_of_Sound)
As I stated, I have researched the topic, declared that I was not an expert. In fact I stated I was a layperson, which is very clearly stated that I should do in the rule cited as the reason for my post removal.
These above links clearly hold that my post was indeed accurate in that the reason sound travels faster in helium than air is because helium is far more energetic as a medium and sound waves are governed by thermal dynamics.
Thank you in advance for your consideration in the restoration of my post.
I am still learning the nuances of ELI5.
I felt that a more verbose reply would be unhelpful in answering the question as asked.
Latest Answers