Re: Free Body Diagram - changes of changes

[John Mallinckrodt <ajm@CSUPOMONA.EDU>]

> The problem of understanding the relationship of acceleration to
> velocity is not an isolated problem.  Economics professors will tell
> you that students have a terrible time understanding the difference
> between the inflation rate and the rate of change of the inflation
> rate.  There have been many instances of US presidents and US
> economic advisors getting this goofed up during press conferences; I
> have witnessed a few of these myself.

In the case of inflation and the rate of change of inflation we are
at least talking about the difference between a first and a second
derivative--a common and at least somewhat understandable confusion.
But politicians and others seem often to have great difficulty
understanding the difference even between things and their FIRST
derivatives.  Take, for example, the national debt and the budget
deficit.  I've interacted with lots of people who think that we
should never have a budget surplus because "government should never
take in more money than it needs" or some similarly confused argument.

--
John Mallinckrodt        mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.