Chapter 12:
Sound
Practice Test
1.
The wreck of the passenger ship Titanic is at a depth of about 3800 m. A sonar unit on a ship emits a sound wave that travels at a speed of 1500 m/s. How long does it take a sound wave reflected from the Titanic to return to the ocean surface?
a.
1.3 s
b.
2.5 s
c.
5.1 s
d.
2.3 s
Hint
2.
A wave traveling in water has a wavelength of 75 m and a frequency of 2 Hz. How fast is this wave moving?
a.
37.5 m/s
b.
150 m/s
c.
75 m/s
d.
2 m/s
Hint
3.
One flute plays a note with a frequency of 443 Hz, and another flute plays a note with a frequency of 440 Hz. What is the frequency of the beats that the flute players hear?
a.
0.993 Hz
b.
883 Hz
c.
194,920 Hz
d.
3 Hz
Hint
4.
At 0°C sound travels through air with a speed of about 331 m/s and through aluminum with a speed of 4877 m/s. How many times longer is the wavelength of a sound wave in aluminum compared to the wavelength of a sound wave in air if both waves have the same frequency?
a.
4546
b.
0.068
c.
14.7
d.
147
Hint
5.
The speed of sound in air at 0°C is 331 m/s, and at 20°C is 344 m/s. What is the percentage change in the speed of sound at 20°C compared to 0°C?
a.
104%
b.
13%
c.
96%
d.
3.9%
Hint
6.
A sonar unit on a ship emits a sound wave. The echo from the ocean floor is detected 2 seconds later. If the speed of sound in water is 1500 m/s, how deep is the ocean beneath the ship?
a.
1500 m
b.
2 m
c.
750 m
d.
3000 m
Hint
7.
What is the frequency of the first overtone of a 440 Hz wave?
a.
880 Hz
b.
1320 Hz
c.
220 Hz
d.
660 Hz
Hint
8.
In a lab experiment, measurements of the speed of sound in air give values of 329.7 m/s, 333.6 m/s, 330.8 m/s, 331.7 m/s, and 332.2 m/s. What is the average value of these measurements?
a.
330.8 m/s
b.
331.4 m/s
c.
331.6 m/s
d.
331.8 m/s
Hint
9.
What is the wavelength of a 440 Hz sound wave traveling with a speed of 347 m/s?
a.
1.5 m
b.
1.3 m
c.
152,680 m
d.
0.79 m
Hint
10.
A sound wave with a frequency of 440 Hz travels in steel with a speed of 5200 m/s. What is the wavelength of the sound wave?
a.
0.085 m
b.
2,288,000 m
c.
11.8 m
d.
5640 m
Hint
