"We" are not in need of getting to the bottom of this. Most of us have
been there and done that.This particular writer, if she chooses to
analyse physics problems, tends to use the Newtonion approximations as
first principles. The good news is my profession doesn't demand those
skills often. I would, however, be interested, as I mentioned earlier,
how you derive conservation of mV from Newton's force/acceleration
relationship. I think you made that claim earlier in this thread.