when the 1st and the 3rd laws of motion cannot explain motion what takes over?

Question

thanks~

Answer 1

Newton formulated these laws of motion and they work for most everything we do. But beyond Newton, Einstein's theories of relativity take over in high speeds or heavy gravity.

For example, Newton's theories of motion could not explain the orbital time of Mercury around the sun. But using Einstein's equations, because Mercury is near the massive sun, the answers came out perfectly.

Answer 2

newtons laws are also called classical laws, as they can universally explain d classical (macroscopic) particles. but, when the size of these bodies become very small, the quantum laws explains its motion, position, etc. de broglie, einstein, plank,.... hav formulated laws for these kinds of particles.