Inertial vs Non-Inertial Frames
In physics, frames of reference are used to describe the motion of an object. An inertial frame of reference is one in which Newton's first law of motion holds true, meaning an object will remain at rest or in uniform motion unless acted upon by an external force. On the other hand, a non-inertial frame of reference is one in which Newton's first law does not hold true due to the presence of acceleration or rotation.

Inertial Frame
- In an inertial frame, Newton's laws of motion are valid without any need for additional forces.
- The frame is not accelerating or rotating with respect to any other frame of reference.
- Examples of inertial frames include a car moving at a constant speed on a straight road or an airplane cruising at a constant altitude.

Non-Inertial Frame
- In a non-inertial frame, fictitious forces such as centrifugal force or Coriolis force may need to be introduced to explain the motion of objects.
- These frames are accelerating or rotating relative to an inertial frame.
- Examples of non-inertial frames include a car taking a sharp turn or a rotating platform.

Differences
- Inertial frames follow Newton's laws without any additional forces, while non-inertial frames may require fictitious forces.
- Inertial frames are not accelerating or rotating, whereas non-inertial frames are.
- Objects in inertial frames move with constant velocity unless acted upon by an external force, while objects in non-inertial frames may experience apparent forces due to acceleration or rotation.
Understanding the distinction between inertial and non-inertial frames is crucial in accurately describing the motion of objects in different scenarios.