Super fun activity for a rainy day - send balloon rockets flying across the room. My kids had so much fun with this one - trying out different combinations to see which rockets could fly fastest - great fun and lots of learning going on too!
|Under 15 minutes
- Drinking Straw
- Kite String (or other strong thin string or thread such as a fishing line)
- Thread the string through the drinking straw.
- Tie the end of the string on something stable at one end of the room (e.g. the back of a chair).
- Extend the string to about 1-15 feet, pull tightly and fasten to another stable object at approximately the same height as the other end (e.g. another chair back or a door handle).
- Blow up the balloon.
- Whilst still holding the balloon tightly to prevent it deflating, tape the balloon to the underside of the drinking straw using a couple of pieces of tape. Then gently pull the balloon and drinking straw to one end of the string.
- Let go of the balloon and watch it fly along the string.
- Try adding 2 balloons and watch your rocket go faster and further; or attach objects to the balloon (e.g. passengers) and watch them hitch a lift. You can change the angle of the string also and see how this effects the distance travelled by the rocket.
- Round balloons work just fine for this project - but the long thin balloons work even better! Be sure to put a piece of tape at each end of the straw / balloon to get maximum speed...
- How does it work: It's all about Newton's Third Law of Motion: for every action there's an equal and opposite reaction. As you release the balloon, the energy of the air escaping from the balloon produces a forward motion called thrust which propels the balloon along the string. Real rockets work in much the same way - as the rocket fuel is burned, vast amounts of hot gases are produced which propel the rocket forward as they escape. For a more detailed explanation see this website: www.csiro.au
- Be careful when doing this project with younger kids - The stretched string could cause injury should a child run into it.
- If you are interested in extending this science project, there are some great ideas on this website: www.green-planet-solar-energy.com
I had seen this demonstration at a hands-on science workshop at a zoo. Then, as a birthday gift, my son received a space science kit and this was one of the projects. So, it's quite popular. My son had fun blowing up the balloon, and he was especially excited to release the air from the balloon and watch it fly along the string. I was explaining to him that this is a demonstration of one of Newton's laws, and to my surprise, he told me it was Newton's third law - I guess science camp is paying off.