Name:

Sound Wave Notes Fill-in

  1. Sound waves are ________________________ (compression) waves.
  2. Sound travels through _________________ , _________________ and _________________ .
  3. Medium Speed of sound (m/s)
    Air at 0 °C
    Air at 20 °C 343
    Air at 100 °C
    Helium 965
    Fresh water (25°C)
    Sea water (25°C) 1533
    Wood 3828
    Steel
    Stone 5971
  4. Velocity = ________________________ x ________________________
    1. The musical note middle C has a frequency = ________________________ Hz.
    2. The velocity of sound in air is 343 m/s.
    3. wavelength = 343 m/s / 262 Hz = ___________ meters
  5. ________________________ - The ________________________ of a sound wave.
  6. ________________________ - The ________________________ of the wave.
  7. Doppler effect - The apparent change of sound ________________________ as a sound source moves towards and away from the observer.
    1. When getting closer to the sound source the velocity of motion ________ to the velocity of the wave.
    2. The pitch (frequency) is ________________________ .
    3. When moving away from the sound source the velocity of motion ____________ from the velocity of the wave.
    4. The pitch (frequency) is ________________________ .
  8. Decibel - Measurement of the power of the sound wave.

    Sound intensity decreases with the ________________________ of the ________________________ from the source.

    1. Threshold of hearing = ______ dB
    2. Whisper = ______ dB
    3. Purring cat = 25 dB
    4. Normal conversation = 65 dB
    5. Noisy restaurant = ______ dB
    6. Power mower = 100 dB
    7. Threshold of pain = 130 dB
    8. Jet aircraft take-off = ______ dB