Question

Explain the validation of Newton’s laws in an inertial framework by bringing examples of absolute and relative movements.

Answer 1

Inertial frame of reference is that frame of reference which is at rest with respect to an object moving with constant velocity. Therefore, non accelerating frame of refrence is called inertial frame of reference. Newtons laws are not valid in non-inertial frame of references.

Netwon’s laws of motion only apply to inertial frames, which are the frames which obey the Newton's first law. The laws work only in inertial frames because they are formulated based on the existence of inertial frames.

Since the Newton's law are so useful, we want to use them even in the non-inertial frames. Therefore, we artificially make some additional terms, which is known as the pseudoforces.

To understand this concept, let's assume that there is a person standing still on the ground and there is a truck moving with some acceleration let's say that the acceleration is a.

1. So the person standing still on the ground observes the person in the truck to be going forward with acceleration a.
2. Whereas the person in truck sees the person who is standing still going back with acceleration a.

So the observation in which case is right?

It's in case 1 as the truck is going forward with acceleration and the person is standing still.

Whereas in case 2 the person observes the person standing still to be going back with acceleration a which is wrong!

We call case 1 as inertial frame of reference and case 2 as non- inertial frame of reference.

As explained above the observation in the case of non inertial frame is wrong so that's is the reason that Newton's laws are not applicable to non inertial frame of reference