Speed of Saturn V at first staging?

David Spain wrote:
I found this PDF,
http://www.klabs.org/history/reports...1970023342.pdf
and the velocity in figure 1 starts off at about 405 m/s, which is the
speed of the rotational speed of the Earth at that latitude. So it is
relative to space, not to the Cape.

Have to be careful here, equations and numbers used in guidance computer
calculations may not be the same as those issued by the press office.

I would have assumed when 'downrange' velocity numbers are used, the reference
point would be the launch point with an initial velocity of 0, not guidance
numbers that have to take into account Earth's rotational velocity. Is that
not a correct assumption? Would it not be in error to mix the two? I would
think you'd have to be careful about that.

Dave