- Newton's first law states: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. This is also called the law of inertia.
- Law two states: The relationship between an object's mass m, its acceleration a, and the applied force F is F=ma. Acceleration and force are vectors; in the law the direction of the force vector is the same as the direction of the acceleration vector.
- The third law is: For every action there is an equal and opposite reaction.
- Sir Isaac Newton published his three laws of motion in 1687 in his work "Philosophiae Naturalis Principia Mathematica."
- In conjunction with Newton's law of universal gravitation, the laws of motion validated Kepler's laws of planetary motion.
- Newton's laws of motion explain everyday motion, but they are not accurate at all speeds, scales or under all conditions.