1. Sound is a mechanical wave that travels through air or water and is audible to humans. 2. Sound waves can be longitudinal or transverse, with longitudinal waves having areas of compression and rarefaction and transverse waves having crests and troughs. 3. The speed and properties of sound depend on factors like the medium it travels through, temperature, and humidity.

2. WHAT IS SOUND ?
sound is a vibration that audible by
mechanical wave of pressure and
displacement, through a medium such as air
or water.

3. SOUND WAVES ARE DIVIDED INTO TWO PARTS:-
1. LONGITUDINAL WAVES.
2. TRANSVERSE WAVES.

4. SOUND TRAVELS IN THE FORM OF WAVES.
WAVE:- IT IS A VIBRATORY DISTURBANCE IN A
MEDIUM WHICH CARRIES ENERGY FROM ONE
POINT TO ANOTHER WITHOUT THERE BEING A
DIRECT CONTACT B/W TWO POINTS.
IT IS OF TWO TYPES:-
1. LONGITUDINAL WAVE.
2. TRANSVERSE WAVE.

5. LONGITUDINAL WAVES:-
A WAVE IN WHICH THE PARTICLES OF MEDIUM
VIBRATE BACK AND FORTH IN SAME DIRECTION
IN WITH THE WAVE IS MOVING.
IT IS OF TWO TYPES:-
1. COMPRESSION.
2. RAREFACTION.

6. 1. Compression:- It is the part of
longitudinal wave, in this wave the
particle of medium are very close to
one another, then they normally are and
there is momentary reduction in volume
of medium.

7. 2. RAREFACTION:- IT IS THE PART OF
LONGITUDINAL WAVES IN WHICH THE
PARTICLES OF MEDIUM ARE FARTHER APART
THEN THEY NORMALLY ARE AND THERE
MOMENTARY INCREASES IN THE VOLUME OF
MEDIUM.

8. TRANSVERSE WAVE:-
IN THIS THE PARTICLES OF MEDIUM MOVE
UP AND DOWN ‘AT RIGHT ANGLE’ IS
CALLED TRANSVERSE WAVE.
IT IS OF TWO TYPES.
1. CRUST .
2. TROUGH.

9. IT IS HUMP OR ELLIVATION PART OF
TRANSVERSE WAVE, WHICH IS ABOVE THE ZERO
DISTURBANCE.
It is hollow and depression part of
transverse wave, which is below the zero
disturbance.

11. 1. Sound can travel through in solid,
liquid gas.
2. Sound travel 15 times faster in
steel then air.
3. Sound cannot travel through
vaccum.

12. 1. It depends on nature of material
through which it travel.
2. it depends on temperature.
3. it depends on humidity of air.

13. THE BOUNCING BACK OF SOUND WHEN IT
STRIKE A HARD SURFACE IS CALLED
REFLECTION SOUND.
Sound
reflected here
Reflected
sound waveIncident
sound wave
Clock
Ear
Normal

14. TWO LAWS OF REFLECTION OF SOUND.
1. THE INCIDENT SOUND WAVE, REFLECTED
SOUND WAVE AND THE NORMAL AT THE POINT
OF INCIDENCE LIES ON THE SAME PLAIN.
2. ANGLE OF REFLECTION OF SOUND IS ALWAYS
EQUAL TO INCIDENCE OF SOUND.

15. The repetition of sound caused
by reflection of sound waves is
called echo.

16. APPLICATION OF REFLECTION OF SOUND.
1. MEGAPHONE:- IT IS A LARGE CONE
SHAPED DEVICE FOR AMPLIFYING THE
VOICE OF A PERSON WHO SPEAKS INTO IT.

17. It is a medical instrument
used by doctor for listening
produced with in the human
body mainly heart and lungs.
THREE PARTS:-
1. Chest piece 2. Ear piece
3. Rubber tube.

18. THE SOUND HAVE TOO HIGH FREQUENCY WHICH
CANNOT BE HEARD BY HUMAN BIENG SARE
CALLED ULTRA SOUND.
FREQUENCY= 20,000 HZ

19. RECIEVERTRANSMITTER
SHIP
Sea bed

20. SONAR:-
SONAR STAND FOR SOUND NAVIGATION AND
RANGING. SONAR IS A DEVICE THAT USES
ULTRA SONIC WAVES TO MEASURES THE
DISTANCE, DIRECTION AND SPEED OF UNDER
WATER OBJECT.
It is calculated by the method:-
2d = v * t

21. ADVANTAGES OF ULTRA SONIC WAVES:-
1). IT IS A HIGH FREQUENCY DUE TO WHICH
THEY CAN PENETRATE INTO SEA WATER TO A
LARGE EXTENT.
2). IT CANNOT BE CONFUSED WITH OTHER
SOUNDS OR NOISES.

22. HUMAN HEARING
sound wave
vibrates ear drum
amplified by
bones
converted to
nerve impulses in
cochlea