Ludwik has asked some good questions in his recent post, about the energy
first approach.
It is my impression that the vast majority of popular introductory level
books present Work first, energy second. I'm sure they and the authors do
it for a reason; even if it is only for the bad reason of pedagogical
inertia; but I suspect it is more than that. Do any folks on the list have
opinions why Work first is the approach of the vast majority of texts? Even
the PER based text by Reif is essentially a Work first approach (Work and
Kinetic Energy introduced simultaneously and Potential energy later.
For those interested in a text that does do what John D suggests, check out
the "Physics 2000" "text". The author proceeds rather closely to how Ludwik
outlines things; I haven't read yet how he handles springs and 1/2*K*X^2 for
spring potential energies.
Last minor point. I don't think Ludwik's worry about students not being
able to "multiply vectors" (by which I assume he means the dot product of
vectors) is a problem. There exist texts that teach that early on, well
before week 5.
I personally don't like that approach of an opening chapter that does vector
algebra along with dot and cross products. But it is done in a minority of
texts. I prefer to introduce the dot and cross products as needed.