The laws of motion Isaac Newton (1642-1727) published Principia Mathematica in 1687. In this work, he proposed three " laws"of motion Law 1: An object subject to no external forces is at rest or moves with a constant velocity if viewed from an inertial reference frame Law 2: For any object, FNET =2 F=ma Law 3: Forces occur in pairs: FAB =-FBA (For every action there is an equal and opposite reaction More in following chapters Physics 121: Lecture 3, Pg 6Physics 121: Lecture 3, Pg 6 The Laws of Motion Isaac Newton (1642 - 1727) published Principia Mathematica in 1687. In this work, he proposed three “laws” of motion: Law 1: An object subject to no external forces is at rest or moves with a constant velocity if viewed from an inertial reference frame. Law 2: For any object, FNET =  F = ma Law 3: Forces occur in pairs: FA ,B = - FB ,A (For every action there is an equal and opposite reaction.) More in following chapters