14.2 Sound Waves

• Sound waves propagate through a medium by compressing and expanding its particles
• Sound waves move particles perpendicularly to their direction of propagation.

  False
• Order the mediums from slowest to fastest speed of sound:

  1️⃣ Air (20°C)

  2️⃣ Water

  3️⃣ Steel
• What is the primary characteristic of sound waves that distinguishes them from transverse waves?

  Longitudinal particle movement
• Match the medium with its approximate speed of sound:

  Air (20°C) ↔️ 343 m/s

  Water ↔️ 1,480 m/s

  Steel ↔️ 5,960 m/s
• What two properties of a medium affect the speed of sound waves?

  Density and elasticity
• Order the wave properties from most fundamental to derived:

  1️⃣ Wavelength

  2️⃣ Frequency

  3️⃣ Speed
• What is the key difference between longitudinal and transverse waves in terms of particle movement?

  Parallel vs. perpendicular
• Denser and more elastic mediums allow sound waves to propagate faster.

  True
• Unlike transverse waves, sound waves compress and stretch the medium
• Sound waves propagate through a medium by compressing and expanding its particles
• Match the wave type with its particle movement:

  Longitudinal waves ↔️ Parallel to wave direction

  Transverse waves ↔️ Perpendicular to wave direction
• The frequency of a sound wave is measured in Hertz
• The speed of sound in a medium depends on its density and elasticity

  True
• Why does sound travel faster in denser mediums?

  Closer particle spacing
• Match the wave type with its particle movement:

  Longitudinal waves ↔️ Parallel to wave direction

  Transverse waves ↔️ Perpendicular to wave direction
• What properties of musical instruments affect the sound waves they produce?

  Shape and material
• String instruments produce sound waves by vibrating strings
• Order the steps in sound wave production by a wind instrument:

  1️⃣ Air is blown into the instrument

  2️⃣ Air column vibrates inside

  3️⃣ Sound waves are produced
• What type of waves are sound waves?

  Longitudinal mechanical waves
• What is the wavelength of a sound wave?

  Distance between peaks or troughs
• The frequency of a sound wave is measured in Hertz
• What formula relates the speed, wavelength, and frequency of a sound wave?

  $v =$$λf$
• Sound waves travel faster through denser mediums.


  True
• Sound waves cannot exist in a vacuum
• Sound waves compress and stretch the medium as they move.


  True
• Sound waves travel faster through mediums that are denser and more elastic
• Why can sound waves not travel in a vacuum?

  No particles to vibrate
• What type of waves are sound waves?

  Longitudinal mechanical waves
• Sound waves can travel in a vacuum

  False
• What is wavelength (λ) in sound waves?

  Distance between peaks
• How is the speed of sound calculated?

  $v =$$λf$
• Order the mediums from slowest to fastest sound speed:

  1️⃣ Air (20°C)

  2️⃣ Water

  3️⃣ Steel
• In which medium does sound travel fastest according to the table?

  Steel
• Denser and more elastic mediums allow sound waves to propagate faster

  True
• Percussion instruments create sound waves by striking or plucking their surface


  True
• Match the phenomenon with its definition:

  Resonance ↔️ Amplification of wave amplitude

  Interference ↔️ Combining of two or more waves
• What is the phase alignment in constructive interference?

  In phase
• Destructive interference occurs when sound waves are out of phase