why does a paper cut in spiral start
rotating when held over a candle flame
Answers
Answer:
How can you make a paper spiral spin without touching it?
Globule
Experiment: A paper spiral
Hypotheses: Ask children how they can make a paper spiral turn without touching it. The early childhood educator could have prepared a paper spiral ahead of time. Showing it to children may help them suggest one or more hypotheses.
Material:
• One sheet of paper per child
• Scissors
• String
• A needle
• Crayons
• A lamp with an uncovered incandescent light bulb
Manipulations:
1. Trace (or ask your early childhood educator to trace) a spiral like the one shown here. It should fill approximately ¼ of your sheet of paper. Leave about 1 cm between each line.
2. Decorate your spiral with crayons.
3. Carefully cut your spiral on the line, starting at the outer tip.
4. Ask your early childhood educator to use the needle to punch a hole in the centre of your spiral.
5. Thread the string through the hole and tie a knot.
6. Hold the string and position your spiral over the lamp. It turns!
Explanation: The air around the lamp heats up. Since hot air is lighter (less dense) than cold air, the air that surrounds the lamp rises and pushes on your spiral, causing it to spin.