Which Magnetic Pole?

Move the known magnet and work out which end of each pivoting magnet is north.

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Pivot magnets

Drag the known magnet with your finger or mouse — or tap the canvas and use ← → ↑ ↓.

Think about it

  1. Slide the known magnet slowly from one side to the other. Which end of each pivoting magnet follows the red end of the known magnet?
  2. The end that turns toward the known magnet's north pole is south. Why must that be true?
  3. Move the known magnet along the row. Does every magnet turn the same way at the same moment, or do they respond one after another?
  4. Press Flip known magnet. Predict what the pivoting magnets will do before they move. Were you right?
  5. For a challenge, press Hide poles. With the labels and colours gone, can you still work out which end is north from the motion alone?