In which material does sound travel fastest?

In which material does sound travel fastest?

• A. Air
• B. Water
• C. Steel
• D. Wood

Answer: (C)

Vibrations move fastest in materials that are very stiff but not extremely dense. The speed of sound depends mainly on how quickly a push can be transmitted through the material, which is why stiffness (elasticity) plays a big role: stiffer materials pass along the compression and rarefaction parts of the wave more rapidly. Among the options, air is very soft and compressible, so sound travels slowly. Water is denser and a bit stiffer than air, so it’s faster than air but still not as fast as solids. Wood varies a lot with type and direction, but its overall stiffness and density usually don’t exceed that of steel. Steel has a very high stiffness, and despite its density, the rapid transmission of vibrations makes sound travel fastest through it.

Vibrations move fastest in materials that are very stiff but not extremely dense. The speed of sound depends mainly on how quickly a push can be transmitted through the material, which is why stiffness (elasticity) plays a big role: stiffer materials pass along the compression and rarefaction parts of the wave more rapidly. Among the options, air is very soft and compressible, so sound travels slowly. Water is denser and a bit stiffer than air, so it’s faster than air but still not as fast as solids. Wood varies a lot with type and direction, but its overall stiffness and density usually don’t exceed that of steel. Steel has a very high stiffness, and despite its density, the rapid transmission of vibrations makes sound travel fastest through it.