The Production and Properties of Sound
by
Cynthia D'Souza
This lesson was created as a part of the SMART website and is hosted by
the Illinois Institute of Technology
1. The velocity of sound in air is --------- to ambient
temperature at
any set atmospheric pressure.
| A. directly proportional |
B. indirectly
proportional |
C. inversely
proportional |
D. unrelated |
2. If air pressure remains constant and temperature rises, the speed
of
sound
| A. stays the
same |
B.
rises |
C.
falls |
D. varies erratically |
3. A French experiment carried out in the 18th century determined the
speed of
sound by measuring the time, over a fixed distance, between
| A. bird calls and bird
flight |
B. thunder and
lightning |
C. the flash and boom of
cannons |
D. telegraph signals and
light flashes |
4. The speed of sound at human body temperature (37oC) is
| A. 310 m/s |
B. 365 m/s |
C. 332 m/s |
D. 354 m/s |
5. During a sound check, the technician at a rock concert adjusted a
circuit
to hear the sound from the stage through the air at the same time he
could hear
it through his headphones. The afternoon temperature was 30oC,
the evening performance was 13oC, and the soundboard was
200 m from
the stage. How much of a delay did the technician hear at the evening
performance?
| A. 0.02
s |
B. 0.2
s |
C. 0.1
s |
D. 0.6 s |
6. A Concorde jet flies at Mach 1.2 at an altitude of approximately
10 km
(speed of sound + 1050 km/h), and a normal jet flies at 600 km/h. How
much
faster does the Concorde fly than a normal jet?
| A. nearly twice as
fast |
B. more
than twice as fast |
C. about one and
one-half times
as
fast |
D. more than three times as fast |
7. The threshold of hearing is considered to be
| A. 5
dB |
B. 50
dB |
C.
0dB |
D.20 dB |
8. The threshold of hearing is defined by an intensity of 10-12
W/m2. A conversation has a measured
intensity of
10-5 W/m2.
The intensity in decibels is
9. A motorcycle passing a quiet restaurant produces a sound
intensity
of 75 dB. The sound intensity at the restaurant is 45 dB. The
motorcycle noise
is roughly -----more intense than the sound in the restaurant
| A. 3
times |
B. 100
times |
C. 1000
times |
D. 30 times |
10. The outer ear
| A. directs sound to the eardrum
and helps determine sound direction. |
B.. determines the intensity and
direction of sound |
C. determines the frequency and
intensity of sound |
D. determines the frequency and
direction of sound |
11. The middle ear consists of the
| A. cochlea, Eustachian tube, and
meatus |
B. hammer, anvil and spur |
C. hammer, anvil and stirrup |
D. meatus, semi-circular canal,
and stapes |
12. The human ear is most sensitive to sounds in the range
of
| A. 2000-4000
Hz |
B.100-250
Hz |
C. 10000-20000
Hz |
D. 5000- 10000 Hz |
13. Because the sensitivity of the human ear varies over the audio
spectrum,
many sound systems----- very high and ----very low frequencies to
compensate.
| A. dampen,
dampen |
B. amplify,
amplify |
C. dampen ,
amplify |
D.amplify, dampen |
14. A room with a reverberation of zero is called
| A. an anechoic chamber |
B. an echoic
chamber |
C.
an
isolation
booth |
D. a reverberation tank |
15. The ability of waves to travel round obstacles or through small
openings
is called
| A.
refraction |
B.
reverberation |
C.
reconstitution |
D. diffraction |
16. Waves with longer wavelengths diffract---- waves with shorter
wavelengths
| A. less
than |
B. the same amount
as |
C. more
than |
D. they are not diffracte |
17. Because lower notes are more easily diffracted by openings and
objects
than higher notes, it is usually -----to determine the source of ----
notes
| A. harder,
higher |
B. harder,
lower |
C. easier,
lower |
D. impossible, higher |
18. At night, when a layer of cool air is close to the ground and
warmer air
is above, sound tends to
| A. refract back towards the
ground |
B. refract away
from the
ground |
C. reflect back to its
source |
D. diffract over a wide area |
19. A stone is dropped into a well that is 100 m deep. The
temperature is 25oC. How much time elapses between the
moment when the stone is dropped
and the
moment when the sound of the stone hitting the bottom is heard?
| A.1.0
s |
B. 0.5
s |
C. 4.8
s |
D. 8.5 |
20. A boat race is started by a cannon blast on the shore. the ships
are
perpendicular to the shore where the cannon is placed. the muzzle flash
cannot
be seen. If the nearest ship is 0.5 km from the cannon and the farthest
ship is
1.0 km from the cannon, how much sooner does the nearest ship hear the
cannon,
if the temperature is 15oC.
| A. 3.0
s |
B. 1.5
s |
C 0.75
s |
D. 2.3 s |
Answers