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The Wagon-Wheel Effect

Why wheels spin backwards in videos

You've watched a car race forward on video while its wheels spun backward. The wheels never did that. So what were you seeing?

You'll find out

  • Why speeding wheels can spin backward
  • The speed that freezes a spinning wheel
  • How helicopters fly with frozen blades

Why it matters

Every camera, from movie sets to the phone in your pocket, sees in snapshots. Anything that spins can fool it.

About 3 min6 interactive slides · 5 questionsLesson 23 · Zone 3

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