Hurricane in a Bottle

Reading Time: 2 minutes

If you have a two-liter bottle and some water, you’ve got all you need to demonstrate to your kids the basics of a hurricane.

This all thanks to The
Naked Scientists
…and you never even have to leave your home.

  1. Fill a two-liter bottle with water

  2. Dump the water out….what happens?  It likely chugs and gurgles as the water slowly empties from the bottle

  3. Fill the two-liter with water again

  4. This time, empty the bottle while you swirl the water around inside the bottle.
    What happens? The water likely pours out much more quickly.  Why?

2literglug_22literglug_2
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When you just dumped the water, the air and water worked against each other the air was trying to enter the bottle while the water was trying to leave the bottle – slowing the process down.

When you swirl the water you create a whirlpool.  This allows air to enter the bottle
while the water is streaming out.  Centrifugal force works in your favor as the bottle narrows to the neck of the bottle – this helps speed up the water and allows it to spray out while air goes into the bottle…just like what happens in a hurricane.  Closer to the center, the air and water swirl much faster than on the outer edges.  Look at the Naked Scientists page on this – they have a decent explanation.

I was cleaning out a two-liter the other night when I decided to swirl the water around.
My youngest son saw what happened and asked to see it again.  This attracted the attention of his older brother.  After several demonstrations they still thought it was pretty cool and asked that I show
Mom.  Not a bad experiment while gathering up the recyclables.

 

[Images from
The Naked Scientists]

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