The Speed of Sound

Science: KS3, topic 3.3.12

Speed of Sound

Sound needs to travel through a medium. The more rigid the medium is, the higher the speed of sound through it. The more compressible the medium is, the slower the speed of sound through it.

Gases

Gases

  • Gases are readily compressible (easy to squash).
  • So the speed of sound in a gas is very slow.
Liquids

Liquids

  • Liquids are more rigid and less compressible than gases.
  • So the speed of sound in liquids is much higher than in gases.
Solids

Solids

  • Solids are significantly more rigid than liquids and gases and are very hard to compress.
  • Therefore, the speed of sound in solids is much higher than in liquids or gases.

Test yourself on The Speed of Sound

  • In science fiction films we often hear sound effects of battles taking place in outer space. Considering the conditions needed for sound waves to propagate, why are these sound effects unrealistic?

  • A block of rubber is very easy to compress. A block of steel is very rigid and hard to compress. Through which material does sound travel faster?

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