Inertial Reference Frame

Definition

An inertial reference frame is a coordinate system in which Newton's laws of motion hold true and there are no external forces acting on an object. It is a frame of reference that is not accelerating or rotating.

Analogy

Imagine you're sitting in a car that is moving at a constant speed on a straight road. Inside the car, everything appears to be still because you and the objects inside are moving together with the same velocity. This scenario represents an inertial reference frame.

Related terms

Accelerating Reference Frame: A reference frame in which an object experiences acceleration due to external forces.

Non-inertial Reference Frame: A reference frame that is either accelerating or rotating, where Newton's laws of motion do not hold true.

Galilean Principle of Relativity: The principle stating that the laws of physics are the same in all inertial reference frames.