Speed of Sound

[ffutures]

Just experiencing an interesting demo of the speed of sound in air and through the ground - they're pile-driving supports for the new Crossrail power line support gantries this afternoon, about sixty or seventy yards from my house, I'm hearing the sound first followed by some vibration through the ground and my house a fraction of a second later.

Comments

[nelc]

Hmm, isn't the speed of sound in solids faster than the speed of sound in air? Shouldn't you be feeling the vibration first, then hearing it?

Unless it took the long way round, I guess.

[ffutures]

Yes - the direct route is a straight line, the ground route is through the house - underground across the railway cutting, then a few feet up to street level then up two floors to me - say an additional 20ft.