This experiment is fun to do with a few other people so you can race your balloons. Look out for learning about jet propulsion, aerodynamics, mechanics, and friction.
Inflate a balloon. If you want, draw a face or wings or messages on your balloon.
Use two pieces of tape to attach a straw to it. Attach the straw so that its ends are toward the top and bottom of the balloon. Now let the balloon deflate.
Set up the race course. Measure the distance you want your balloon to travel. For example, if you want it to rocket across the room, measure the room. Then cut a piece of wire or string that length. Attach one end of it to the wall at the other end of the room or to a piece of furniture.
Thread the loose end of the wire through the straw on your balloon.
Attach the end of the wire to a railing or chair back in front of you.
All together, blow up your balloons and pinch the neck to hold the air in.
Ready, set, let go! At the signal, let go of your balloon and let it fly along the wire.
WHAT'S GOING ON?
As the air shoots out of the balloon, it propels the balloon along the wire or string. Your balloon may—or may not—zip along the wire or string. It depends on the angle and length of the “racecourse” and the positioning and length of the straw. Balloons don’t go? Consider changing the position of the straw, or using a longer or shorter piece of straw.
ALL PHOTOGRAPHS BY MATTHEW RAKOLA. ADAPTED FROM THE BOOK "TRY THIS: EXTREME" BY KAREN RAMANO YOUNG