はじめまして.素朴な質問をさせてください.力積のIは,ImpactのIだと学んだのですが,運動量のPとは何を意味するのでしょうか?
Wikipediaには次のように書いてありますね.
The origin of the use of p for momentum is unclear. It has been suggested that, since m had already been used for "mass", the p may be derived from the Latin petere ("to go") or from "progress" (a term used by Leibniz