AAPT Logo
TPT Logo
 
   
 

You are not logged in You are not logged into this journal. Log In

The Physics Teacher -- May 2003 -- Volume 41, Issue 5, pp. 286

The Answer Is Forty-Two — Many Mechanics Problems, Only One Answer

Robert H. Romer

Amherst College, Amherst, MA

Full Text: Read Online (HTML) | Download PDF | Buy PDF (US$30) | View Cart
The answer is 42, actually 42 minutes, but what was the question? There are, in fact, a number of physics questions, not at first glance closely related to one another, to which 42 minutes (or perhaps 84 minutes) is the answer. This paper was prompted by one such question, a Figuring Physics item in a recent issue of this journal,1 which called for a description of the motion of a block released on a flat frictionless plate tangent to the Earth's surface. The correct answer given in Figuring Physics was that “the block will oscillate to and fro,”2 but I was disappointed to see that the time of oscillation was not called for. So let us refine the question: “For small-amplitude oscillations, how long does it take for the block to travel from one extreme to the other, i.e., what is the half-period of the motion?” This is the question (actually just one of the questions) to which the answer is 42 minutes, as we can readily calculate. Those who are familiar with The Hitchhiker's Guide to the Galaxy [Douglas Adams (Harmony Books, New York, 1979)] will understand why I chose to ask initially for the half period (42 min) rather than asking the more obvious question, “What is the period?”3

© 2003 American Association of Physics Teachers

KEYWORDS and PACS

Keywords

physics education, teaching, mechanics, oscillations, pendulums

PACS

History
Online Apr 2003

PUBLICATION DATA

ISSN

0031-921X (print)  

Publisher

$abstract.society.value is a Member of CrossRef American Association of Physics Teachers

ARTICLE DATA

Digital Object Identifier
http://dx.doi.org/10.1119/1.1571264

For access to fully linked references, you need to log in.

For access to citing articles, you need to log in.



Close

Your Recent History Recent History Help

Recently Viewed

  1. The Answer Is Forty-Two — Many Mechanics Problems, Only One Answer
  2. Collecting and Recording Bicycle Speed Data by CBL
  3. How Fast Is Your Finger? An Introduction to Photogate Use
  4. Physics in the Art Museum
  5. A Physics Teacher in Europe

AAPT on:

close