Re: force

["Paul Camp" <pjcamp@coastal.edu>]

I wonder if it is really that linear. One of the points Arons and 
others have made very vigorously is that it is not necessary to cover 
each topic in absolutely exhaustive detail before moving on to the 
next, that a cycling back with successive refinements approach yields 
greater benefits.It seems logical, then, that intricately linked 
ideas such as force and acceleration should be developed in tandem 
rather than in succession. If you have two tools, you can fix more 
broken things than you can if you have only one. If a student is 
still thinking of acceleration as another species of velocity, then 
you can point out that this is inconsistent with the result obtained 
from Newton's Laws in the case of a ball on the end of a string 
whirling in a circle. Now we can work on resolving the inconsistency. 
A state of cognitive dissonance is an opportunity to learn; in this 
case, there is a strong motivation to look at how directed motion 
changes because clearly there is *something* gumming up the works 
here -- one thing you know is inconsistent with another thing you 
know. Two floodlights tend to cast fewer shadows than a single one.


> As I mentioned from, the heart of the matter, for me, is getting students 
> to understand directed motion, and how it changes.  If they can recognize 
> that, then you have a chance at getting them to understand the notion of 
> force as cause for those changes.

> Joe

Paul J. Camp                   "The Beauty of the Universe
Assistant Professor of Physics  consists not only of unity
Coastal Carolina University     in variety but also of 
Conway, SC   29528              variety in unity.
pjcamp@coastal.edu                    --Umberto Eco
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