sound waves slide

7/29/2019 Sound Waves Slide

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What is sound?

Sounds are caused by vibrating objects. The string of a guitar, the skin of the drum and tuning

fork vibrate to produce sound.

Turning fork vibration Plucking the guitar


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ANALYSING SOUND WAVES

At the end of this lesson, studentsshould be able to:

Describe sound waves

Explain how the loudness relates toamplitude.

Explain how the pitch relates tofrequency.


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These sound waves are created by the vibration of some object, like a

radio loudspeaker.

Its vibrating diaphragm will caused a series of compression (region ofincreased pressure) and rarefaction (region of decreased pressure)travel through the air away from the loudspeaker.

The resulting succession of compression and rarefaction constitutes the

sound waves. The waves are detected when they cause a detector to vibrate.

Your eardrum vibrates from sound waves to allow you to sense them.


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Describe sound wave

Is a longitudinal wave in nature because

the air molecules vibrate in the direction

which is parallel to the propagation

Needs a medium to propagate.


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What is Amplitude and Frequency

of Sound Waves?


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Amplitude and Frequency of

Waves

Y/cm

t/s

a

-a

0.2 0.4 0.6


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displacement

displac

ement


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Amplitude and Frequency of Sound

Waves

The amplitude of sound waves depends on its

loudness.

The louder the sound, the

bigger is its amplitude.

The slower the sound, the

smaller is its amplitude.


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The frequency of sound waves depends

on its pitch.

The higher the pitch of the sound, the

higher its frequency.


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Questions:

1. Sounds are caused by ______objects.

2. Sound wave is ____________wave.

3. Sound wave needs a _______to propagate.

4. The amplitude of sound wave depends on its__________

5. The louder the sound, the ______is itsamplitude.

6. The _________of sound wave depends on itspitch.

7. The ______the pitch of the sound, the higherits frequency.


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5

4

1 V

2 I

B

6 R

A

7 T

3 I

N

G


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5

4

1

2 L O N G I T U D I N A L

6

7

3


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5

4

1

2

6

7

3 M E D I U M


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5

4

L 1

2 O

U

D 6

N

7 E

S 3

S


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5B

4

I 1

2 G

G

E 6

R

7

3


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5

4

1

2

6 F R E Q U E N C Y

7

3


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5

4

1

2

6

7 H I G H E R

3


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5B

4

L I 1 V

2 L O N G I T U D I N A L

U G B

D E 6 F R E Q U E N C Y

N R A

7 H I G H E R T

S 3 M E D I U M

S N

G


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ANALYSING SOUND

WAVES

At the end of this lesson, studentsshould be able to:

Describe sound waves

Explain how the loudness relates toamplitude.

Explain how the pitch relates tofrequency.


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DO HOMEWORK

Text book on page 12,question no.:

1,3,5 and 7

Read page 15 for the next meeting.


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THE END

sound waves slide

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