Force is considered frame independent because the fundamental quantities it often depends on, such as the separation between objects, are themselves independent of the inertial frame of reference from which they are observed.
While measurements like displacement can vary depending on the observer's frame, the distance or separation between the 2 point masses is also independent (displacement is frame dependent, but not separation). Forces like gravitational force or electrostatic force depend directly on this separation. Since the separation between interacting objects doesn't change from one inertial frame to another, the force depending on this separation also remains the same.
Hence the net force will also be independent of the frame of reference. This principle extends to other types of forces as well. Similarly one can argue for the other forces. Whether it's a contact force, a tension, or a magnetic force, their definitions and magnitudes are rooted in physical interactions that do not inherently depend on the motion of the observer, provided the observer is in an inertial frame.
Hence we consider Force to be independent of frame of reference. This independence is crucial in physics, as it ensures that the fundamental interactions between objects are described consistently regardless of the observer's inertial viewpoint.
Key Takeaways:
- Forces are generally considered independent of the inertial frame of reference.
- A key reason is that the separation between interacting objects is frame independent, unlike displacement.
- Forces that depend on this separation (like gravity between point masses) are therefore frame independent.
- This independence is argued to apply similarly to other types of forces.
