Are discrete models more accurate?

Newton’s second law describes the motion of the center of mass of most objects that we encounter in everyday life, including the complex motion of a spoon when we eat, the acceleration of a car, and even the trajectories of planets and stars. Only if objects move extremely fast, do we need to replace Newton’s second law with Einstein’s theory of relativity, and only if objects are extremely small, do we need to use the laws of quantum mechanics.