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