186 The Physics Teacher Vol. 52, March 2014 DOI:
10.1119/1.4865533
Randall J. Scalise (Southern Methodist University, Dallas,
TX)
Robert Siddon (U. S. Naval Academy, Annapolis, MD)
Jason L. Smith (Richland Community College, Decatur, IL)
Guidelines for contributors: We ask that all solutions,
preferably in Word format,
be submitted to the dedicated email address [email protected].
Each message will receive an automatic acknowledgment.
The subject line of each message should be the same as the name
of the solution file (see the instructions below).
The deadline for submitting the solutions is the last day of the
corresponding month.
We can no longer guarantee that well publish every successful
solvers name; each month, a representative selection of names will
be published, both in print and on the web.
If your name isfor instanceBrian May, please name the file
Mar14May (do not include your first initial) when submitting the
March solution.
If you have a message for the Column Editor, you may contact him
at [email protected]; however, please do not send your
solutions to this address.
As always, we look forward to your contributions and hope that
they will include not only solutions but also your own Challenges
that you wish to submit for the column. Many thanks to all
contributors and we hope to hear from many more of you in the
future! Boris Korsunsky, Column Editor
Physics Challenge for Teachers and Students
Boris Korsunsky, Column EditorWeston High School, Weston, MA
02493 [email protected]
w Defying gravityA small negatively charged ball of mass m is
suspended on a long insulating string. Another small negatively
charged ball is slowly moved by a student toward the first one from
a large distance. Eventually, the second ball is placed at the
original location of the first one. At that moment, the first ball
is elevated a small distance h above its origi-nal position. How
much work is done by the student mov-ing the second ball?
Our December Challenge, Squaring the Circle: Now in 3D! proved
to be tough. However, almost all received solu-tions were correct.
We are pleased to recognize the follow-ing contributors:
Don Easton (Lacombe, Alberta, Canada)Fernando Ferreira
(Universidade da Beira Interior,
Covilh, Portugal)Rickard Fors (Sdra Latins Gymnasium,
Stockholm,
Sweden)Art Hovey (Galvanized Jazz Band, Milford, CT)Jos Ignacio
iguez de la Torre (Universidad de
Salamanca, Salamanca, Spain)Jos Costa Leme (High School
Lanheses, Viana do
Castelo, Portugal)John Mallinckrodt (Cal Poly Pomona, Pomona,
CA)Carl E. Mungan (U. S. Naval Academy, Annapolis,
MD) Thomas Olsen (Northern Virginia Community College,
VA)Joseph Rizcallah (Sagesse High School, Ain Saadeh,
Lebanon)
This article is copyrighted as indicated in the article. Reuse
of AAPT content is subject to the terms at:
http://scitation.aip.org/termsconditions. Downloaded to
IP:150.214.141.83 On: Thu, 06 Mar 2014 15:24:18
