Why does sound travel faster through solids?

Answer 1

Let's see if we can figure this one out. First, sound is mechanical energy. It needs a medium to travel through. The energy is transferred into the medium, and the medium carries it through itself. That's propagation, and you probably already knew most or all of that. But we need to start at the beginning, so let's jump.

When something moves to create sound, either continuously like a guitar string, or "just once" like when a hammer strikes a nail head, the action creates pressure waves or a pressure wave. The pressure wave or waves are actually atoms or molecules "pushing against" each other in response to the action causing the sound. The "pushing against" each other is the transfer of the mechanical energy of sound through whatever is "conducting" that energy. That's how sound is transmitted (and why sound can't travel through a vacuum). The medium is carrying the mechanical energy of the wave. So the action of atoms or molecules shoving each other "over" to conduct the sound, this compression of them, has an opposite action, which we call rarifaction. Let's make a short jump.

When the cone of a speaker moves out and in, it creates compression and rarifaction waves in air. The air conducts these waves out and away from the speaker in the "usual manner" in which the mechanical energy is sent out. The gas atoms and molecules in the air are "shoved out" from the speaker and then are "sucked back" by the speaker. Sound moves via a longitudinal wave where the energy is transmitted along the path of travel of the wave. There is a fair amount of space between the atoms and molecules in air, so when the "shoving" starts, that is, when the vibration or movement of whatever it is that is making the sound begins, there is "room to move" in the gas. The energy isn't transferred as quickly or effectively because of the "loose" nature of the way the atoms and molecules are arranged. Let's jump to a liquid.

In liquids, the atoms and/or molecules are "sloshing around" loosely, but their isn't as much space between the "particles" as there is in air or any gas. The "closeness" of the "particles" is going to allow for a more rapid and more efficient transfer of the mechanical energy of sound. When the "shoving" starts as the mechanical energy of sound is introduced, the "particles" in the liquid are going to conduct the energy better than any gas. Shall we look at a solid? Yes, let's.

In a solid, the atoms or molecules of the sturcture are all "connected together" and can't "get away" from each other when "the shoving" starts as the mechanical energy of sound is introduced. Consider that the "particles" in a solid are all "locked in place" in the structure, and a solid will conduct sound a lot better than a liquid. Faster, too. The medium is more "rigid" than gas or liquid mediums, and this makes all the difference in the world as regards the propogation of sound.

There will be some "exceptions" in this, like trying to transmit sound through, say, foam rubber. You can see the problem there. The spaces in the solid structure and the "tenuous" nature of the material and its geometry will "muffle" sound, or, from the point of view of physics, will absorb and less effectively transmit the mechanical energy of sound. Other than that, if you had a long, continuous beam of, say, steel, and you struck one end with a hammer, the sound would arrive at the other end having traveled through the beam itself sooner than it will having traveled through the air right above the beam. It's that simple and easy. by christian Taylor

Sound waves travel by vibrating neighbouring molecules and transferring the sound energy from point A to point B. So the sound travels fastest in solids as the molecules are very closer together so the vibrations are transferred very quickly from one molecule to another.

Answer 2

Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it.For example, sound waves travel over 17 times faster through steel than through air.

Answer 3

Sound is vibration and the molecules in a solid are closer together in a solid allowing the vibration to travel quicker.