Hooked on Science: Balloon in a bottle

Have you ever tried to blow up a balloon inside a bottle? It's easy if you use science.

Materials

* Balloon

* Empty water bottle

Instructions

STEP 1: Insert the balloon into the empty water bottle and pull the neck of the balloon over the outside of the empty water bottle.

STEP 2: Place your mouth over the opening of the empty water bottle and attempt to inflate the balloon.

Explanation

The air inside the bottle was trapped when you placed the balloon over the outside of the empty water bottle. When you attempted to inflate the balloon the trapped air inside the bottle stopped you from blowing up the balloon. If you force a small hole in the side of the bottle, and then attempt to inflate the balloon, the air you blow inside the balloon will force the air trapped inside the bottle through the hole and the balloon will inflate.

Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website www.hookedonscience.org for webcasts and experiments.