Page 200 - New Medley 3 Semester 2

SOUND

We hear di erent sounds around us like the ringing of the

school bell, the breaking of glass, the blowing of horns, the

rustling of leaves, the shouting of children, the barking of dogs
and the talking of people. Sound is produced only when an
object vibrates.

Talk to somebody and place your ngers on the front side of
your neck. Can you feel the vibrations? Larynx

e sound producing organ in humans is called larynx. It is placed in the throat.

When we speak, air passes through the larynx. is air vibrates the vocal cords
of the larynx and sound is produced.

Noise and Music

Some sounds irritate us. ey are unpleasant to hear.
Such sounds are called noise. e sounds of heavy

tra c, horns, loudspeakers, crackers and people

shouting together create noise pollution. Noise
pollution is harmful to our health. We must try to

avoid noise. We should follow some good habits like Bursting crackers produces noise

speaking so ly and listening to music and watching TV at low volume.
Some sounds make us feel good. ey are so and pleasant to hear. Such sounds

are called music or musical sounds. So music helps in reducing stress.

FORCE

Look at the pictures.

In the rst picture, a boy is pushing a table. In the second picture, a girl is

pulling a chair.

Can you list some examples where
you push or pull things?

A push or a pull makes an object

move. It is a kind of force applied

on an object. us, force is a push or
pull that brings changes in an object. A boy pushing a table A girl pulling a chair

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