What it shows
Moving air can push on slanted blades and make them turn. Wind energy is used the same way in windmills.
The science
When wind hits the curved blades, it pushes them sideways, so the pinwheel turns. The pin acts as an axle, and the bead makes the turning smooth. A stronger breeze makes it turn faster. Wind turbines work on the same idea and make electricity.
Materials
Cost: free. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- A square sheet of paper, 15 cm (free)
- A pencil with an eraser end or a thin stick
- A pin or a drawing pin
- Scissors and a ruler
- A bead or button
Safety
For this project: An adult must cut and press the pin. Keep the pin end blunt with the eraser.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Draw two lines from corner to corner on the square paper to find the centre.
Cut along each line, stopping 2 cm from the centre.
Bend every second corner point to the centre without creasing it.
Hold the points together at the centre and ask an adult to pin them through a bead onto the eraser of the pencil.
Check that the pinwheel turns freely when you blow on it.
Take it outside on a breezy day and watch it spin.
Count spins in ten seconds with a gentle breeze and with a fan.
Write your counts and say which was faster.
What you should see
The pinwheel spins when air blows on it, faster in a strong breeze.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1What makes it turn?
Wind pushing on its blades.
2Where is wind energy used?
In windmills and wind turbines.
3What does the pin do?
It is the axle for turning.
4What happens in a stronger wind?
It turns faster.
Take it further
Attach a thread to the pencil and see if it can lift a feather.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
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