Which reference frame is characterized by Newton's laws applying?

The inertial reference frame is characterized by Newton's laws applying because, in this frame, objects that are not subjected to external forces will either remain at rest or continue moving in a straight line at a constant speed. This behavior is fundamental to Newton's first law of motion, also known as the law of inertia.

Inertial reference frames are those where the observers are not experiencing any acceleration; they can apply Newton's laws without requiring any additional fictitious forces to account for non-inertial effects. For example, an observer in a car moving at a constant speed on a straight, flat road is in an inertial frame, and can accurately describe the motion of objects using Newton's laws.

Conversely, non-inertial reference frames, such as rotating or accelerated frames, present a scenario where Newton's laws do not hold in their simplest forms without introducing fictitious forces (like the centrifugal or Coriolis forces). This is why objects in these frames may appear to accelerate without any real force acting on them, thus complicating the application of Newton's laws.

Overall, the defining characteristic of an inertial reference frame is that it allows for a direct application of Newton's laws, making it a foundational aspect in the study of