Sound Waves

Doppler effect and applications

Definition of Doppler Effect

  1. The Doppler effect refers to the apparent change in the frequency or wavelength of a wave observed by an observer moving relative to the source of the wave.
  2. It occurs in all types of waves, including sound, light, and water waves.
  3. The effect is commonly experienced with sound waves, such as when an ambulance siren changes pitch as it passes by.

Formula for Doppler Effect in Sound

  1. The observed frequency

Characteristics of sound: pitch, loudness, quality

General Characteristics of Sound

  1. Sound is a longitudinal wave that requires a medium for propagation.
  2. Key characteristics of sound include pitch, loudness, and quality.
  3. These characteristics determine how sound is perceived by the human ear.

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Speed of sound, factors affecting speed (medium, temperature)

Definition of Speed of Sound

  1. The speed of sound refers to the rate at which sound waves propagate through a medium.
  2. It depends on the elastic properties and density of the medium.
  3. The formula to calculate the speed of sound is v = √(B/ρ), where B is the bulk modulus and ρ is the density.
  4. In air, the speed of sound is approximately 343 m/s at room temperature (20°C).

Factors Affecting the Speed of Sound

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Production and propagation of sound

Introduction to Sound Waves

  1. Sound waves are mechanical waves that require a medium for propagation.
  2. They are longitudinal waves, where particles in the medium oscillate parallel to the direction of wave travel.
  3. Vibrations in a source generate sound waves, which travel through air, liquids, and solids.
  4. Sound cannot propagate through a vacuum as it requires a medium with particles.

Production of Sound

  1. Sound is produced when an object undergoes
Sound Waves