Sound travels in other media too
{"Image DocumentName": "Sound travels in other media too", "Image ImageDescription": "Doesn\u2019t have to be air \u2013 just has to have an elastic property i.e be able to change shape in response to an applied force and then resume its original shape once force is removed. E.g. putty is not elastic but steel is. Sound generally travels fastest in solids, then in liquids, and slowest in gases. E.g. 15x as fast in steel c.f. air and 4x as fast in water c.f. air. Also, generally less dissipation (ie fading away) in solids and liquids than in air, E.g. Can hear the slight rattles a distant train makes on the rails before you hear it\u2019s noise from the air. E.g. Motors of boats \u2013 sound much louder under water, than above. . i.e. Liquids and crystalline solids are much better conductors of sound. Sound needs a medium \u2013 won\u2019t travel in a vacuum since nothing to compress and expand.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}