The Speed of Sound> We know that sound travels through air - we can hear it! But can sound travel through other things? Put your head under water sometime, in a bathtub or a pool, and have someone gently bang on the side, or click two rocks together in the water. You can easily hear the sound so. . . sound clearly travels through water. Smush your ear against a wooden door, and then knock. Knock, knock! Sound travels through wood! Sound vibrations move through anything compressible (squeezable) - and most everything is compressible, including gasses like air, liquids like water, and solids like wood, steel, or solid rock.
Float in a lake with one ear in the water and the other in the air. Someone does a humongo bellyflop off a dock a mile away. Which ear do you think will hear the sound first? Will the sound travel faster through air, or through the water? It turns out that your water ear will hear the splash in about a second; your air ear, almost 5 seconds. Sound travels slower in air than in liquids like water, and travels fastest in most solids like wood or metal.
