Re: Tension, scalar or vector?

In article <[EMAIL PROTECTED]>,
 Charles Francis <[EMAIL PROTECTED]> wrote:

> In article <[EMAIL PROTECTED]>, Peter R. 
> Oakfield <[EMAIL PROTECTED]> writes
> >Hi. I am in a big argument regarding tension, like in a cord or
> >string. Some knowledgeable people tell me it is a vector; others say
> >it is a scalar. The implications are important. I think it is a
> >scalar, because it has no unique direction and I cannot imagine the
> >meaning of negative tension. Who is right? Could someone please help
> >me?
> 
> Its a vector because it is directed along the string. Negative tension 
> is compression.

A 'vector' would change sign under the transformation (x,y,z) -> (-x,-y,-z)

The tension in a string doesn't - it's a tensor, or a pseudo-vector.

So I guess nobody wins the bet.

Charles