2. Sound
•Sound waves are produced by
vibrating objects. They are
propagated through a medium from
the source.
•Sound waves are longitudinal waves.
•Particles of the medium vibrate in the
direction of wave motion.
3. •The material through which
sound travels is known as the
medium.
•The medium can be a solid,
liquid, or a gas. Sound needs a
medium to travel.
•It cannot travel through vacuum.
8. Intensity depends on the amplitude of
vibration and the area of vibrating body
perpendicular to the direction of wave
motion.
9. Pitch depends on the frequency of vibration.
Pitch is the frequency of a sound as perceived by
human ear. A high frequency gives rise to a high
pitch note and a low frequency produces a low
pitch note. The pitch of sound goes up and down.
10.
11. Temperature is a condition that
affects the speed of sound.
Molecules at higher
temperatures have more energy,
thus they can vibrate faster.
Since the molecules vibrate
faster, sound waves can travel
more quickly.
12. The speed of sound in room temperature air is 346
meters per second. This is faster than 331 meters per
second, which is the speed of sound in air at freezing
temperatures. For every degree rise in temperature, the
increase in the speed of sound is 0.6m/s. At 00C, the
speed of sound in air is 331m/s. At 10C, the speed will
become 331.6m/s. This is determined by the use of the
equation:
v = 331m/s + (0.6m/s0C) T
where v is the speed of sound
T is the temperature of the air.
At a temperature of 10C
V = 331m/s + (0.6m/s0C) (10C)
V = 331.6 m/s.
13. • Speed of sound
358.0 m/s
343.6 m/s
330.4 m/s
From the above figure, notice that the speed of sound varies directly with the
temperature-as the temperature increases, the speed of sound also increases.
14. Waves have some common
properties. The study of the
properties of sound waves is
called acoustics. Sound waves
are reflected when they hit a
barrier.
15. • Reflection of sound waves off of surfaces can lead
to one of two phenomena - an echo or
a reverberation. Multiple reflections are called
reverberation. A reverberation often occurs in a
small room with height, width and length
dimensions of approximately 17 meters or less.
This best fits the bathroom which enhances the
voice.
16. Refraction of sound on the other
hand is describe as the change in
speed of sound when it
encounters a medium of different
density. Sound travels faster in
hotter media. This change in
speed of sound during refraction
is also manifested as sort of
“bending” of sound waves.
