Question

Pleases explain in details Define a reference frame and then an inertial reference frame. Give example of both inertial and non-inertial reference frames.

Answer 1

In it's simplest form, the explanation is that all inertial frames of reference are in constant motion with respect to each other (ie non - accelerating).Physical laws take the same form in all inertial reference frames.
In a non-inertial reference frame, the laws vary according to the acceleration of that frame with reference to an inertial frame, and the usual physical forces must be supplemented by fictitious forces.

example : If the vehicle is not accelerating, the passenger is in an inertial frame of reference. This is because no acceleration means your velocity is constant. If the vehicle is accelerating, the passenger is now in a non-inertial frame of reference.