Try this little experiment I guarantee you will have hours of fun with it either alone or like me if you use it at a Kids Science Party.
What you will need
- 1 balloon
- 1 plastic, polystyrene or paper plate
- 1 sharp pencil
How to do it
- Measure and mark out a 7 or 8mm diameter hole in the centre of the plate.
- Pass the neck of the balloon through the hole so most of the balloon is on the flat side (the bottom of the plate) and the inflation hole is on the eating side of the plate.
- Inflate the balloon but don’t tie it off. Let the balloon and plate rest on a large surface (with the balloon pointing up). The balloon and plate should float across the table.
- Experiment with different sized holes – remember the hole must be large enough to let through enough air to float the hovercraft but not too big that it will allow the air through too quickly.
What is happening?
As the air comes out of the balloon it is at a higher pressure than the surrounding air. Newton’s Law comes into play again. This air is pushing down on the table and the equal and opposite reaction defined in Newton’s Third Law is to push the plate up. The concaved nature of the plate helps to retain a cushion of air for longer than if you used a simple flat surface.
Share your experiment...
All experiments must be conducted in the safest possible way. An adult must be present wherever it states one is required. Never do anything dangerous with chemicals or fire for your sake and those around you.