At home for 5-11 11-14
- Level Elementary
What you need
- A plastic cup or yoghurt pot
- A damp cloth
- Smooth string
- Pencil or biro
- Make a hole in the bottom of a plastic cup with a pencil or biro
- Cut a length of string, thread it through the hole, and tie a knot in the end inside the cup to stop it from slipping back through the hole
- Take the damp cloth and hold it tightly around the string. Now pull the cloth firmly along the string to hear the cup cluck
Results and Explanation
Pulling the cloth along the string makes it vibrate and produce a faint sound. But the cup and air around it also vibrate so the sound is amplified enough for us to hear it.
These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.