Sound Practice
Name ________________________________
1. Two major classes of waves are longitudinal and transverse. Sound waves are
________________. What does this mean?
2. What is an echo?
3.
4. A ______________________of a sound wave corresponds to a crest of a
transverse wave.
5. A ____________________of a sound wave corresponds to a trough of a
transverse wave.
6. Label #4 & #5 on the diagram above.
7. When the crests of one wave overlap the crests of another wave, there is
_______________ interference and an increase in __________________.
8. When the crests of one wave overlap the troughs of another wave, there is
________________________ interference and a decrease in ____________.
9. Is the following sentence true or false?
Constructive sound interference is a useful property in antinoise technology.
10. Beats are the result of the alternate cancellation and reinforcement of two
sound waves of
a) the same frequency b) slightly different frequencies c) different volumes
11. Two notes with frequencies of 66 and 70 Hz are sounded together.
The resulting beat frequency is
a) 4 hertz
b) 68 hertz
c) 136 hertz
12. What happens to the speed of sound as the temperature changes?
13. Circle the letter of the speed of sound in dry air at 0°C.
a. 20 m/s
b. 330 m/s
c. 60 m/s
d. 1200 m/s
14. The speed of sound at normal room temperature is about __________.
15. Is the following sentence true or false? During a thunderstorm, you hear the
thunder before you see the lightning.
16. Sound waves travel fastest in
a) solids b) liquids c) gases d) same speed in each
17.What happens to a sound wave if the amplitude is decreased? Increased?
18.What are some everyday uses of reflected sound?
19. Compared to the wavelengths of high-pitched sounds, the wavelengths of lowpitched sounds are (long) (short).
20. The changed pitch of the Doppler effect is due to changes in
(wave speed) (wave frequency).
21. When an automobile moves toward a
listener, the sound of its horn seems relatively
a) low pitched
b) normal
c) high pitched
and when moving away from the listener, its
horn seems
a) low pitched
b) normal
c) high pitched
22. A sound wave produced by a car horn is heard 45 m away .133 s later.
a) What is the speed of the sound of the car horn in air?
b) If the sound wave has a frequency of 275 Hz, what is its period?
c) What is the wavelength?
23. Dynamite is set off 40,000 m away, how long will it take to hear the sound?
Sound travels 340 m/s.
24. If Susan shouts and hears an echo 5 seconds later, how far away is the
barrier? Sound travels at 340 m/s.
25. If one tuning fork has a frequency of 320 Hz and another has a frequency of
360 Hz, what is the beat frequency produced from these two forks?
Ex 1: Sitting on the beach at Coney Island one afternoon, Sunny finds herself beneath the flight path of the
airplanes leaving Kennedy Airport. What frequency will Sunny hear as a jet, whose engines emit sound at a
frequency of 1000. Hz, flies toward her at a speed of 100.0 m/s?
Ex 2: In the previous example, what frequency will Sunny observe as the jet travels away from her at the same
speed?
26. One foggy morning, Kenny is driving his speed boat toward the Brant Point
lighthouse at a speed of 15.0 m/s as the fog horn blows with a frequency of 180.0
Hz. What frequency does Kenny hear as he moves?
27. You pull over to allow a fire truck with sirens blaring to pass. If the truck is
moving toward you at a speed of 30 m/s, what is frequency of the 92 Hz siren as
it approaches you? What is the frequency as the truck moves away from you?