Sorry, we don't have any more space
This
activity is different from all the previous ones because this time the
pressure inside the bottle will become higher than outside and this
extra pressure inside the bottle will not let the water in!
1. Place a funnel on top of an empty plastic bottle.
2. Use modeling clay/plasticine around the bottle opening and around the funnel to make it airtight.
It
is a little harder with playdoh than with modeling clay (or even the
putty sold in plastic eggs that you can find at dollar stores) as
playdoh doesn't stick well to the plastic (bottle and funnel).
3. Start pouring water through the funnel.
4.
Stop pouring water when the water starts rising in the funnel.
Initially water starts flowing into the bottle but it slows down to a
trickle and then stops. Instead, water starts rising in the funnel (and
stays there).
Explanation:
If you have succeeded in using the modeling clay to make the bottle's
opening airtight, then air can flow in or out only through the funnel.
When you pour water through the funnel, air can't escape out. As the
water level rises inside the bottle, the air is squeezed. The
compressed air exerts enough pressure to deny the gravity from
pulling the water into the bottle.
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