Project 3 - Take a sheet of paper and draw a spiral

Last updated at July 13, 2026 by

Take a sheet of paper and draw a spiral on it, as shown in Fig. 7.17a. Cut the paper along the spiral. Suspend the cut spiral above a burning candle, as shown in Fig. 7.17b. Observe what happens and provide an explanation for your observation.
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The paper spiral rotates, because hot air rising from the candle pushes it.

Key Points

  • The candle heats the air around its flame.
  • Warm air is lighter, so it rises upward.
  • This rising warm air is a convection current.
  • The moving air pushes against the paper spiral.
  • The spiral spins as the warm air rises through it.
  • This shows convection — heat transfer by the movement of air.
Rising warm air (convection) spins the paper spiral above the candle.
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