The Second Law of Motion (v1)
An object’s acceleration is equal to the force applied in terms of the object’s mass (a=F/m). Or, the force applied on an object equals the object’s acceleration times the object’s mass (F=ma).
“Mutationem motus proportionalem esse vi motrici impressæ, & fieri secundum lineam rectam qua vis illa imprimitur.”
(“The change of motion is proportional to the magnitude of the impressed motive force, and to be made along the right line by which that force is impressed.”) [From “Philosophiæ Naturalis Principia Mathematica” by Sir Isaac Newton. Translated by Ian Bruce, 17centurymaths.com/contents/newtoncontents.html]