Materials
- Glasses with stems
- Water
- Food colouring
How to make it
- Half fill a glass with water, then dip your finger in it.
- Move your other hand to the base of the glass and hold firmly. Press down the rim of your glass with your wet finger.
- Slowly move your finger around the rim of the glass. You should be able to make a ringing sounds come from the glass.
- You could add food colouring to the glasses and play a colourful tune for your friends.
What’s happening?
The glass ‘sings’ because it is being made to vibrate by your moving finger. Changing the size or the amount of water alters the sound. A big glass filled with water makes a low note, and a small glass with a little water makes a high note.
If you’d like to find out about more fun activities like this, check out Make and Do Science.
