Hooked on Science: Discover air pressure by making a hole in a bottle

What happens when there is a hole in the bottle holding your favorite drink? It all depends on if the lid is on the bottle.

Materials

* Plastic soda bottle

* Nail

* Water

Instructions

STEP 1: Using the nail, create a hole in the side of the bottle close to the bottom.

STEP 2: Place your finger over the hole, completely fill the bottle with water, and then quickly screw the lid onto the bottle.

STEP 3: Remove your finger from the hole. What happens?

STEP 4: Unscrew the lid from the bottle. What happens?

Explanation

When you removed your finger from the hole, the water did not flow from the hole in the bottle since the lid was still secure on the bottle keeping the air pressure out of the bottle. When you removed the lid from the bottle, the air pressure pushed downward on the water forcing the water through the hole in the bottle.

Jason Lindsey is a Science Outreach Educator with Hooked on Science. Check out his website "Hooked On Science" at hookedonscience.org for webcasts and experiments that might get you hooked on science. Send him your science questions at jlindsey@hookedonscience.org. More science experiments can be found at www.semissourian.com.