Fun Friday -making spooky sounds!

Keeping with the Halloween Science theme, this week I share a cool experiment perfect for the spooky season!

Make a Spooky Sound Cup!

All you need is ….

a plastic cup
a paper clip
some twine or string
a knife or scissors
a piece of kitchen paper
water

What to do…

1. Tie the paperclip to one end of the twine.
2. Ask an adult to make a small hole in the base of the cup, using the knife or scissors.
3. Hold the cup upside down and thread the twine through the hole. The paperclip will stop the twine from coming all the way through.
4. Fold the kitchen paper in half and then quarter and then dip it in water. You want it wet but not dripping.
5. Holding the cup in one hand, fold the wet kitchen paper over the twine with the other hand and hold between your thumb and first finger.
6. Pull the wet kitchen towel down along the twine, pinching between your fingers all the time.
7. You should notice it makes a really spooky sound.

You can try this experiment without the wet kitchen paper, just wet your thumb and finger instead; Does it make a different sound?

You could also see what happens if you use a different type of twine, or some ribbon, or use a larger cup!

So what is happening?…

As you pull the kitchen paper down along the twine the friction between the two makes the twine vibrate.  These vibrations travel through the air and  bounced around the walls of the upturned cup – amplifying the vibrations so we get to hear the spooky, screechy sound!

Hope you have some Spooky Fun with this experiment.  Stay tuned for lots more over the Halloween Season!