Final answer:
Newton's laws of motion apply best to objects that are macroscopic and moving at speeds much less than the speed of light, such as several billiard balls interacting on a billiard table.
Step-by-step explanation:
The objects for which Newton's laws of motion apply best are those that are at scales larger than subatomic particles and moving at speeds much less than the speed of light. This is the realm of classical mechanics. Therefore, the best example of an object where Newton's laws of motion apply would be several billiard balls interacting on a billiard table. These objects are macroscopic and move at speeds that are well within the range where classical mechanics and Newton's laws are an excellent approximation. It is important to note that modern physics has revealed limitations to the accuracy of Newton's laws. These laws do not apply accurately to objects moving at near-light speed or at the scale of subatomic particles. Instead, the theory of relativity and quantum mechanics would need to be applied in such scenarios.