How can you make a cup sound like a duck? All you need is a plastic cup, some string, a pair of scissors and a wet cloth!

Equipment

• Plastic cup
• String
• Scissors
• Something sharp to make a hole in the bottom of the cup
• Wet cloth

Method

1. Carefully make a hole in the middle of the bottom of the plastic cup
2. Cut some string and feed it through the hole
3. Tie a large knot at the end of the string
4. Run a wet cloth down the length of the string. What do you hear? Repeat this with just a piece of string with no cup on the end. Do you notice a difference?

The Science

The wet cloth creates friction on the string which produces a vibration. You can hear a faint squeak on the string with no cup on the end. When you add the cup, this amplifies the noise, creating a much louder sound.

Health and Safety

If the children are making their own, they should use children’s safety scissors.