Build a lighthouse
What's it all about?
We all know that if you let go of a blown-up balloon it flies around the room making a rude sound. But can we use a balloon in a more controlled way to power a ‘rocket’ guided on a piece of string? It sounds easy, but you have to think carefully if you want to make a fast, long distance rocket instead of a stationary rude thing.
Are you ready for the challenge?
This activity is easy and fun. The main problem is how to stop the air coming out of the balloon too fast. This is where the drinking straws and paper clips help.
Nearly all groups will burst some balloons in the building and testing stages, so have some extras handy. It helps to make it a timed exercise (how long depends on how they are getting along with the problem). The string for the ‘rocket testing facility’ must be stretched tight, and free of knots.
Beware the howls of protest when the students remember that it doesn’t matter how fast their balloon rocket goes, only how far!
Health and Safety
When considering carrying out a practical activity with a class, you must check your local health and safety rules. Make an appropriate risk assessment and try the activity yourself first.
Per group of students:
- 4 × party balloons
- 4 × clean drinking straws
- 4 × paper clips
- 1 × roll of sticky tape
- 1 × pair of scissors
- 2 × A4 sheets of card (or US Letter size)
- 4 m length of string
In the lab: