Exploring Structure Using Waves (AQA GCSE Physics): Revision Note

Exploring Structure Using Waves

Higher Tier Only

• Sound waves can be used to analyse structures that are hidden from direct observation

• Examples of the use of sound waves

  • Echo sounding used by shipping to detect the ocean floor

  • Ultrasound used to look inside the human body

  • Ultrasound crack detection to find cracks in rail tracks

  • Reflection seismology to detect oil and gas underground

  • Seismic activity (Earthquakes) can be used to investigate the structure of the Earth

• The properties of a substance that allow the detection of hidden structures are:

  • Reflection

  • Absorption

  • Transmission

  • The speed of sound in the substance

• Each type of substance will produce different amounts of reflection, absorption and transmission

• Each type of substance will also transmit a sound wave at a specific speed

  • Sounds will travel faster in solids than liquids and sound travels faster in liquids than gases

• Certain structures will reflect a proportion of the sound wave and transmit the rest

  • Some substances will absorb sound waves with very little reflection

• By detecting the amount of sound reflected and the speed of the wave the hidden structure can be identified