Science Secrets · Drawing 14 of 40
A Telephone Made of String
Light and Sound
Your voice makes the cup’s base vibrate. The tight string carries the vibrations to the other cup. Your friend can then hear the message. Hello!
Did you know?
The string needs to stay tight to carry the vibrations well.
Look together
Where does the string meet each cup?
An idea to try
An adult prepares two cups joined by string. Speak gently, then compare a tight string and a loose one.
For the adult reading along
A little more to discover
A string telephone transmits vibrations mechanically, without an electric circuit. The string attaches to the cup bases and does not touch furniture.
Sources and illustration notes (1)
Simplified scene and shapes. Models, imagined comparisons and enlargements do not preserve all real measurements.
These links lead to other websites. Explore them with an adult. References identify the institution and the related lesson; some linked pages are in French.
- Science World: Telephone LinesYour voice makes the can (or paper cup) vibrate, and the taut string carries the vibration to the other one.
Page prepared on October 12, 2026. Illustrations are simplified for colouring.
This drawing is from the book Science Secrets to Colour
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