Re: revision of Newton's Second Law

[Rondo Jeffery <RJEFFERY@WEBER.EDU>]

Leigh wrote:

> In a classical mechanics textbook by Synge and Griffith the
> Second law is formulated as:
>                     _       _
>                     P = k m f
>                    _              _
> where, I interpret, P = phorce and f = fastering. Those guys
> must have really hated students!
>
> Leigh

I don't know what edition of Synge & Griffith you are using, Leigh.  But in my 1959 edition (3rd ed.), when the 'Law of Motion' is introduced (p. 27), they write it as:
_     _
F = kma
      _     _
where F and a are bolded to indicate vectors.  The constant k is described as 'a universal positive constant, the value of which depends only on the choice of units of force, mass, length, and time.'
_         _
F, m, and a are the usual force, mass, and acceleration.

Sounds like they must have corrected confusing nomenclature from an earlier edition.

Rondo Jeffery
Weber State University
Ogden, UT 84408-2508
rjeffery@weber.edu