Why do you think sound travels faster in steel than it does in wood? (Hint: Think about the densities of the two materials, and how the particles might be arranged.)

If sound waves of the same energy were passed through a block of wood and a block of steel, which is more dense than the wood, the molecules of the steel would vibrate at a slower rate. Sound moves faster through denser air because the molecules are closer together in dense air and sound can be more easily passed on.