Pinwheels usually work by putting them in the wind or blowing on them. In this experiment, we will experiment with using another force to spin the pinwheels.
Student Guide
Hot Shot Spinner
Experimenting with heat and pinwheels.
How does rising heat and blade tilt affect a pinwheel?
This resource was originally published in PhysicsQuest 2011: Spectra Heats Up!
How does rising heat and blade tilt affect a pinwheel?
- Tart pan
- Pencil (sharpened)
- 4 birthday candles
- Molding clay
- Lighter or matches
Intro
Before the experiment
As you go up in a building, does it get warmer or colder? Why?
What can cause a windmill or pinwheel to turn?
Setting up
Sharpen the pencil and secure it point side up with the clay.
Put clay on the bottom of the four birthday candles and secure close to the pencil.
You will be making a pinwheel/windmill out of the tart pan. Make six, 2-inch radial cuts in the tart pan making sure to leave the middle intact to hold the “windmill” together.
Twist the blades 45 degrees counter-clockwise.
Carefully balance the tart pan windmill on top of the point of the pencil.
During the experiment
Collecting data
Very carefully light one of the birthday candles. Record what happens to the pinwheel.
Now light the second, third and fourth candles, each time recording how the motion of the pinwheel changes.
Again light one or more of the candles with the blades twisted counter-clockwise as they were for the first experiment. Which direction is the pinwheel spinning?
Now twist the blades in the opposite direction, changing their orientation by 180 degrees. Light one or more candles. Which way is the pinwheel spinning now?
Analyzing data
What were your results?
- What happened to the pinwheel when you lit the first candle?
- How did the pinwheel’s motion change when you lit more candles?
Conclusion
Why do you think the orientation of the blades affects the direction of the pinwheel?
How are the direction of the pinwheel blades and the direction of the spinning related?