The Physics
Opus in profectus


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  1. Draw the magnetic field around the following arrangements of magnets. Start each field line on a given blue dot and extend it until it hits another magnet or hits the edge of the bounding box.
  2. Write something.
  3. Write something.
  4. Write something completely different.


  1. Two small, lightweight, pivoting magnets are placed near one another with their north poles facing inward as shown in the diagram below. What final arrangement will these two magnets have?

    Cartoon representation

  2. Using a strong magnet, it is possible to pull the iron out of a fortified breakfast cereal. It is not possible to do this to the iron in your blood. (I don't care what you saw Magneto do in that X-Men movie, it can't be done.) Why is this? How is the iron in breakfast cereal different from the iron in human blood?