This document discusses how sound propagates through different materials and the factors that affect the speed of sound. It explains that sound waves can travel through solids, liquids, and gases by transmitting energy from one molecule to the next. The speed of sound is fastest in solids due to their dense molecular structure, and it is faster in liquids than gases. Temperature, humidity, and air pressure can impact the speed of sound, with warmer and more humid conditions causing it to travel faster through air. The document also describes characteristics of sound like pitch, loudness, and timbre, and includes a table listing the speed of sound in various materials.

2. How does sound
propagate?
Can sound waves also
travel in other media
like solids and liquids?

3. Prepered: By:Sir Levi L. Loreto Jr.
Sound

4. Activity 1 My Own sounding Box
Figure 2

5. Procedure
1.Cut and design your shoe box as shown in figure 2
2.Put the rubber bands around the box. Make sure that the rubber
bands are almost equally spaced and that the rubber bands are
arranged according to increasing thickness from the lower end to
the other end of the box.
3.Use your finger to pluck each rubber band. Listen to the sound
produced.
4.This time use the fingers of one hand to stretch one of the rubber
bands. Pluck the rubber band with the fingers of the hand and
observe.
5.Repeat step 4 with the other rubber bands.

6. Sound
The sensation perceived by the sense
of hearing. : mechanical radiant energy
that is transmitted by longitudinal
pressure waves in a material medium
(such as air) and is the objective cause
of hearing.

7. Solids, Liquids and gases differ in the way the molecules, when
sound propagates, the energy it carries is transferred from
molecule to molecule.
Sound travels fastest through solids. This
is because molecules in a solid medium
Solid
Sound travels faster in liquids than in
gases because molecules are more tightly
packed.
Liquids
Gas
Sound waves which propagate in a gas contain
lighter molecules, and fewer of them per
volume, than in liquids or solids.

8. 3 Charactirestics of
Sound
1. Pitch
2. Loudness
3. Timbre

9. Pitch sound
• Position of a single sound in the complete
range of sound. Sounds are higher or lower in
pitch according to the frequency of vibration of
the sound waves producing them.
• Refers to the highness or lowness of sound.
• The frequency of a wave dictates the pitch of
a sound.

10. Lower frequency Higher frequency
Lower sound Higher sound
Lower pitch Higher pitch

11. Audible Frequencies
2o Hertz (Hz) to 20,00(Hz)
Ultrasonic Frequencies
Above 20,000(Hz)
Infrasonic Frequencies
Below 20 hz

12. Loudness
• making a lot of noise, or the amount of noise something or
someone makes:
• The loudness of their arguing worried me, but then I
realized that they were just excited. Differences in
loudness are measured in decibels.
• Refers to how soft or how intense the sound is
• Can be determined by the amplitude of the sound
• Consider as a psychological sensation that differs form
different people.

13. Higher Amplitude Lower Amplitude
Larger Energy Lesser Energy
Higher Intensity Lower Intensity

14. Device can measure Loudness is Oscilloscope
Oscilloscopes can also identify the pitch of a sound
signal by measuring the time between two peaks,
which is called frequency.

15. Not capable to transmitting sound is VACUUM

16. Sound can not travel through a vacuum
because sound needs vibration of atoms,
particles and molecules for its propagation
while the vacuum is an empty space
containing no atoms, particles and
molecules which can propagate sound
waves.

17. Timbre
• describes those characteristics of sound which
allow the ear to distinguish sounds which have
the same pitch and loudness. Timbre is then a
general term for the distinguishable
characteristics of a tone.
• TONE QUALITY
• Used in differentiating two different sounds
that have the same pitch and loudness

19. Materials Speed of Sound V(m/s)
Air (0℃)
He(0℃)
H(0℃)
Water
Seawater
IronandSteel
Aluminum
Hard wood
331
1005
1300
1440
1560
5000
5100
4000
The table below shows the speed of sound in different materials.
speed of sound in different materials

20. 3 Factors affecting the Speed of Sound
1.Atmospheric pressure
2. Relative Humility
3.Atmosphere Temperature

21. Atmospheric pressure
air pressure has no role to play in deciding
the speed of sound because pressure and
density both contribute to the velocity of
sound equally and thus cancels each
other out. Hence, Air pressure has no
effect on sound speed.

22. Relative Humility
The speed of sound in air increases with the
increase in humidity, because the density of
humid air is less than the density of dry air. As
the density of the medium decreases, the speed
of sound in the medium increases. Hence, the
speed of sound is faster in humid air than the
dry air.

23. Atmosphere Temperature
The average temperature of the atmosphere at Earth's
surface is 14 °C (57 °F; 287 K) or 15 °C (59 °F; 288 K),
depending on the reference.
Hot Temperature
Temperature is also a condition that affects the speed of
sound. Heat, like sound, is a form of kinetic energy. Molecules
at higher temperatures have more energy, thus they can
vibrate faster. Since the molecules vibrate faster, sound waves
can travel more quickly.

24. Cold Temperature
colder and more dense. This means sound
waves spreading out from someone at
ground level are refocused back down
toward the ground. The sound follows a
curving path, and it travels farther under
those conditions.

25. Application

26. Quiz 6

27. Direction: Write the correction Letter in 1/4 sheet of
paper.
1.Which of the following object will produce sound ?
A.soft objects C. vibrating objects
B.radio stations D. objects under pressure
2.Which of the following best describes a high
frequency sound ? it has
A.low pitch C. low energy
B. high pitch D. And B

28. 3.Compared to a thin string of the same length and tightness, a t
string produces sound of ?
A.The same pitch C. higher pitch
B.Lower pitch D. lower that higher pitch
4.A sound wave is a
A.longitudinal wave C. standing wave
B.transverse wave D. shock wave
5.Which of the following is NOT capable of transmitting sound ?
A.air C. seawater
B.Ice D. vacuum