Page 27 - Science and Technology Std 3

FOR ONLINE USE ONLY
DO NOT DUPLICATE

In Figure 2, the boy drops a stone into a basin full of water.
Water waves show how sound waves travel by spreading.
FOR ONLINE USE ONLY

Activity 4 To examine the way sound travels through
cotton string

Materials Hard paper, glue and a cotton string

Procedure

(i) Fold the paper to form two speaker shapes by using glue.

(ii) Join the two speakers using a long cotton string.

(iii) Tell your friend to call you from one end of the speaker.

(iv) Hold one speaker on your ear while your friend is calling.

(v) Can you hear the sound through the cotton string?

(vi) Please write what you hear.

Figure 3 Transfer of sound through a string

When one pupil calls from one speaker, another pupil hears
the sound that passes through the cotton string. This shows
that sound travels through a cotton string.

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Ministry of Education, Science and Technology
Science and Technology 3.indd 20 03/08/2019 11:01