SLIDE SHOW : F2 CHPTER 10

CHAPTER 10:

Sound Waves

10.1 Characteristics of Sound Waves

Caused by vibration



Vocal
cord

1. Sound requires medium to transfer

Vacuum

Sound energy is transferred through
vibration of particles in the form of waves

Sound waves

Prove that:

Sound
requires a
medium to
propagate

Cannot travel through vacuum

2. Sound is transferred very rapidly in
solids, compare to liquids and gases

SPEED OF TRANSFER • Particle arranged very close
OF SOUND IN • Vibration caused nearby

SOLIDS particle also vibrate
• Sound transferred rapidly

SPEED OF TRANSFER • Particle arranged  loose
OF SOUND IN • Sound vibration transferred

LIQUIDS LESS rapidly

SPEED OF TRANSFER • Particle arranged  far apart
OF SOUND IN • Sound vibration transferred

GASES VERY slowly

Prove that: Propagate at different
speeds in different

medium

air flour water

Compare the loudness of the
sound produced

3. Sound can be reflected (echo)

Hard and smooth surfaces
are good sound reflectors



4. Sound can be absorbed

Soft and rough surfaces are
good sound absorbers

Good absorber of sound
• soft and rough surface
• like curtain, carpet)

Sound
absorber
in cinema

Sound
absorber
in studio

Prove that: Sound can be reflected
and absorbed

As a conclusion, SOUND…

Produced by vibrations
Needs a medium to travel (can

travel through solids, liquids and
gases. Cannot travel through
vacuum)

Can be reflected (echo) or
absorbed

10.2 Loudness and Pitch of Sound

Increasing Louder sound is
amplitude produced

Increasing Higher pitch is
frequency produced

Doppler Effect - Apparent change in
frequency



10.3 Phenomenon and Application
of Reflection of Sound Waves

ECHO

produced when sound
waves are reflected from
a hard surface to the
listener

An echo can be heard in places like..

Gorges

Halls
Caves

Tunnels

DO THIS..!!!!!
If you feel less
confident with
yourself

Application of Reflection of Sound
Waves

Sound wave hit different surfaces
 Different reflection of sound wave
 can provide variety of information / images

ULTRASOUND

• Sound wave with a frequency of more than 20 000 Hz
• Cannot be heard by human, can be heard by animals

1. Shipping sector Detect underwater
object / deep of

seabed

2. Fishery sector
Detect

location of
fish

3. Medical sector

4. Estimation of distance by bats

Bat is not blind. But
they use ears more
than eyes. They find
things through echos

LIMITATIONS OF HEARING

HEARING AID PUBLIC ADRESS
SYSTEM
STETHOSCOPE