Answer all questions either in the spaces provided or on a separate sheet of paper. Remember to employ proper problem-solving techniques throughout. You must show all work, including equations, substitutions, and units.

f = 1/T

where **v****wave** is the velocity of the wave (m/s), f is frequency (Hz),

L is wavelength (m), T is period (s), and t is air temperature (degrees C).

where **v****wave** is the velocity of the wave (m/s), m is mass (kg), l is string length (m) and **T **is tension (N).

Carbon Dioxide

Air

Helium

Ethyl Alcohol

Water (pure)

Water (seawater)

Lead

Wood

Iron and Steel

Aluminum

Glass

259

331

965

1207

1498

1531

1200

4300

5000

5100

5170

B = 10 log (I/Io)

f = fo(**v**/**v **-** v****s**)

f = fo(**v**/**v **+** v****s**)

(for source approaching observer)

(for source receding from observer)

where f is frequency of source (Hz), fo is observed

frequency (HZ),** v** is wave velocity in medium (m/s),

where B is intensity in decibels (dB), I is intensity (watt/mexp2),

Io is 10exp-12 (watt/mexp2)

1. Calculate the length of a sound wave which possesses a frequency of 350 Hz and is traveling through air at a temperature of 15 degrees C.

2. A stretched string has a length of 1.5 m and a mass of 0.25 kg. Calculate the necessary string tension for the string to produce waves with a velocity of 5 m/s when plucked.

3. Calculate the length of a sound wave which possesses a frequency of 300 Hz and is traveling through an air temperature of 20 degrees C.

4. Calculate the period of a wave with a frequency of 12,000 Hz.

5. Calculate the distance from a sound source to an observer if the waves require 3 s of travel time through 25 degrees C air.

6. Calculate the intensity factor between a 100-dB source and a 60-dB source.

7. A train whistle possesses a natural frequency 1500 Hz. If the train is approaching a station at a velocity of 30 m/s, calculate the frequency of the whistle perceived by an observer standing at the station, given an air temperature of 30 degrees C.