Re: time squared & time cubed

[Brian Whatcott <inet@INTELLISYS.NET>]

At 05:09 PM 1/16/02, John Denker wrote:
> ...consider the
> flexure of a springy plank, such as a high-diving board.  If
> you make the board thicker by a factor of X, leaving the
> other dimensions the same, its stiffness goes up by a factor
> of X to the third power.  Calling it X cubed is a bit of a
> misnomer;  there is no cube of size X involved.

?
Let me amplify this idea a little - it will not fly in this form,
with electricians  who bend conduit by hand - or with machinists
 who know about deflection of say boring bars with force applied, e.g

<http://www.mmsonline.com/articles/060105.html >

The rule in question is:
Twice as thick, four times the cantilever deflection for constant end force:
 twice as long, eight times the deflection for a constant end force.
(Notice the concrete examples?)

Brian W



Brian Whatcott
  Altus OK                      Eureka!