I Feynman:"Laws of Dynamics" vs "Law of Dynamics"

1. Mar 23, 2016

Odious Suspect

This is an observation, not a criticism. I noticed that in The Feynman Lectures on Physics Vol-I, Chapter 9
Newton's Laws of Dynamics in section 9.5 he speaks of "the law of dynamics" in the singular

"That is where the law of dynamics comes in. The law of dynamics tells us what the acceleration is."

It's clear from the grammatical context that this is no mere typo. He is specifically intending Newton's Second Law, $F=\frac{dmv}{dt}$. The terminology ingrained in my mind for Newton's three laws is "Newton's Laws of Motion" (which Feynman offers as an alternative).

If I wanted to be exceedingly pedantic, I could say that his inconsistent usage is in error by the very fact that it is inconsistent. I prefer to look upon it as an artistic nuance giving us insight into the workings of his mind.

2. Mar 27, 2016

couragerolls

I thought section 9.5 was to explain what eqn 9.12 signifies and the relation of force and thus acceleration with the displacement!! well you only find that one in second law. I mean Newton's second law is sort of like the one with the that kind of relation. I think!!