This Week's Puzzle

This assignment is due before 9 AM, Friday, September 29th, 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!

"A Work Week"

Consider the figure above. The blue ball at (-1,1,0) carries a charge Q, and the green ball at (1,-1,0) carries a charge -Q. I wish to move a small positive test charge, q, from (0,-3,0) to (0,3,0) by one of two routes:

Route 1: straight along the y-axis
Route 2: a path with two diagonal elements passing through the point (-2,0,0)

Which of the following statements is true?

  1. I do more work using Route 1 than Route 2.
  2. I do more work using Route 2 than Route 1.
  3. I do zero work in either case.
  4. I do an equal, positive amount of work in either case.
  5. I do an equal, negative amount of work in either case.
  6. There is not enough given information to decide.

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


This site is made possible by funding from the National Science Foundation (DUE-9981111).

©2000 IUPUI, all rights reserved.
©2001 A. Gavrin and G. Novak, all rights reserved.