This Week's Puzzle

This assignment is due before 9 AM, Friday, November 3rd, 2000.



  • Puzzle solutions are due by 9:00 AM on Friday of each week.
  • Puzzles are worth 5 points of extra credit each.
  • Answers must be accompanied by valid reasoning. Just like the tests, the answer alone isn't enough!
  • Each week, the first student to submit a correct answer will recieve the stylish 251 T-shirt.
  • Previous winners get a "virtual t-shirt." No shirt, but a chance to win a prize with actual value at the end of the semester (often a book, or maybe software).
  • Please enter your solution in the text area at the bottom of this page. DON'T FORGET TO GIVE YOUR NAME!

"The Snake"
The figure above shows a piece of flexible wire lying on a frictionless table top. The wire can slide around and change its shape freely, but it cannot move perpendicular to the table.

Part a
If a current were to begin to flow clockwise in the wire, which of the following would happen? You may ignore the magnetic field of the Earth.

  1. The wire would tend to stretch out into a circle
  2. The wire would contract down to a tangled mess
  3. Nothing
  4. There is not enough information to tell.
Part b
If the current went counterclockwise, would that affect your answer to part a? How?

Don't forget to explain your answer as clearly as possible.


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