The Rocket Pinwheel experiment perfectly demonstrates Sir Isaac Newton's Laws of Motion. Make your own scientific discovery with the help of Science Boffins!
What you will need
- 1 balloon
- 1 pencil with an eraser on one end
- 1 drawing pin - be careful as these can be sharp! Ask an adult to help with this part of the experiment.
- 1 flexible drinking straw
- Sticky tape
How to do it
- Slip the long straight end of the straw into the neck of the balloon and use a short piece of sticky tape to secure the balloon to the straw.
- The balloon should inflate when you blow through the straw.
- Bend the other end of the straw at right angles – the bent end of the straw should be sideways/horizontally and not point vertically up.
- Balance the straw and balloon on an outstretched finger and mark the balance point. Push the pin through the straw at the balance point and continue pushing the pin into the eraser of the pencil (see image below).
- Spin the straw a few times to ensure the hole is big enough.
- Inflate the balloon and watch the straw inside the balloon spin!
What is happening?
This is Sir Isaac Newton’s Third Law of Motion in action! The force of air coming from the balloon is called ‘thrust’. Newton’s Third Law states that for every action there is an equal and opposite reaction. The reaction in this case pushes against the end of the straw causing the apparatus to spin.
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.