Sound

• Sound waves can be transmitted from one medium to another
• Sound waves


  • Move through the air by air particles vibrating side to side
  • Can pass from air to a solid medium
• Examples of sound waves passing between media

  • Microphone - sound waves cause paper cone to vibrate
  • Human ear - sound waves cause eardrum to vibrate
• Normal human hearing has a frequency range of 20 Hertz to 20,000 Hertz
• Frequencies outside the normal human hearing range may not be able to cause the eardrum to vibrate
• Wave speed


  The speed at which a wave travels
• As wave speed changes when passing between media

  The wavelength also changes
• The frequency of a wave does not change when it passes between media
• Frequency


  Determines the pitch of a sound wave
• Amplitude


  Determines the loudness of a sound wave
• Sound waves can only move through a medium, they cannot pass through a vacuum
• Sound waves can be reflected, creating an echo
• Wavelength


  The distance between two consecutive points on a wave with the same phase
• Frequency


  The number of oscillations or cycles a wave completes per second
• Amplitude


  The maximum displacement or magnitude of a wave from its equilibrium or mean position
• Speed


  The rate at which a wave travels through a medium
• Period


  The time taken by a wave to complete one oscillation or cycle
• Sound waves can be described by their frequency (number of oscillations per second) and amplitude (height of wave).
• Sound waves are longitudinal waves that require a medium to travel through, such as air or water.
• The sound level meter is used to measure the intensity of sounds.