Page 102 - ScienceStd4

Activity 6

Identifying how sound transfers through air
FOR ONLINE READING ONLY
Observe what happens when a bell rings at school.

1. Where does the sound come from when the bell rings at

school?

2. From which direction do pupils gather?

3. In which direction do sound waves travel?

4. What have you discovered on how sound travels through
the air?

5. What is the importance of sound energy in our everyday

life?

When sound is produced, air particles vibrate and collide.

These vibrations cause oscillations, creating sound waves.
Sound waves spread through vibrating objects. These objects
transfer sound by vibrating surrounding particles. For example,

an airplane’s sound reaches the ear through vibrating air
molecules. The sound is transmitted from the plane to the ear
via air.

Reflection of sound

The reflection of sound occurs when sound waves bounce
off a surface. A reflected sound is called an echo. This can
be observed in spaces where sound hits reflective surfaces.
Examples of reflective surfaces are walls or large structures.

The time it takes for sound to return determines the distance of
the surface.

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SCIENCE AND TECHNOLOGY STD 4.indd 95 14/01/2025 18:38