Re: Cause and effect.

[John Mallinckrodt <ajmallinckro@CSUPomona.Edu>]

On Mon, 31 Mar 1997, Donald E. Simanek wrote:

> Is "cause and effect" really helpful here? Can it sometimes be a trap?
> (etc.)

I think it is fair to say that we all (not just students) grow accustomed
to thinking about the single quantity that often appears on the left side
of an equation as somehow being "the result of" the quantities that appear
on the right. This is certainly at least computationally the case when we
use the equation as a "formula."  Courses in programming languages
probably don't help. 

Take "F_net = ma" for example.  The equation is simply "a relationship" 
between three quantities.  I wouldn't want to argue strongly that F_net is
*not* "a result of" m and a, but I certainly wouldn't want that to be the
primary implication either.  Certainly students should understand why the
equation a = F_net/m might be preferable, but they should also clearly
understand that it doesn't make *any* diference in how we apply the
equation. 

John
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