Sir Isaac Newton developed gravitation theories at age 23 in 1666. His three laws were presented in 1686 in "Principia Mathematica Philosophiae Naturalis". Newton's laws revolutionized science and explained planetary orbits
Every force occurs in pairs: action and reaction are equal and opposite. The attribution of action and reaction is arbitrary
Force is a push or pull that can change an object's velocity unless balanced. Force is a vector quantity with magnitude and direction. SI unit of force is newton (N), represented by symbol F
Every particle attracts every other particle with force proportional to masses and inversely proportional to distance squared. Law published in Principia Mathematica in 1687, first great unification of gravity and astronomy. Equation: F = Gm1m2r, where G is gravitational constant (6.674×10⁻¹¹ m³⋅kg⁻¹⋅s⁻²)
Energy transfers during car crashes between vehicles and stationary objects. Newton's first law states objects remain in motion unless acted upon. Newton's third law explains equal force between colliding objects
Force equals mass multiplied by acceleration (F = ma). Force is a vector quantity with magnitude and direction. Force can be expressed in Newton (N) or kilograms per second squared (kg/m/s²)