Re: g

["Daniel L. MacIsaac" <Dan.MacIsaac@NAU.EDU>]

> I know in Giancoli physics down is usually neg. and the only reason I can
> find is that the standard coord system "down" is neg.
Actually texts 'lie' or are less-than-complete about vectors all of
the time to 'make things easier', which can sometimes be appropriate.  They
also typically are less than complete when describing the direction of
centripetal accelerations and forces.  I use this as an opportunity
to introduce hat notation myself.  Try to make coordinate specification
an explicit step in solving mechanics problems; this would clear up the
difficulty (in college at least).

Dan M

Dan MacIsaac, Assistant Professor of Physics and Astronomy, Northern AZ Univ
danmac@nau.edu          http://purcell.phy.nau.edu         PHYS-L list owner