Materials:
1. Two plastic cups or yoghurt pots.
2. A string (up to about 15 meters long)
Instruction:
1. Ask a grownup to punch a small hole in the bottom of the plastic cups.
2. Thread one end of the string through one cup and tie a knot inside the cup.
3. Do the same to the other end of the string and tie a knot inside the second cup.
4. Ask a friend to hold the other cup and try to stretch until the string is tight.
5. Try to whisper into the cup while your friend listen with the other.
Explanation:
The sound of your friend's voice makes the string vibrate, carrying the sound to your ear.
