Introduction

As we saw in Chapter 2, Newton's second law of motion is only valid in inertial frames of reference. Unfortunately, we are sometimes forced to observe motion in non-inertial reference frames. For instance, it is most convenient for us to observe the motions of the objects in our immediate vicinity in a reference frame which is fixed relative to the surface of the Earth. Such a frame is non-inertial in nature, since it accelerates with respect to a standard inertial frame due to the Earth's daily rotation about its axis. (Note that the accelerations of this frame due to the Earth's orbital motion about the Sun, or the Sun's orbital motion about the galactic center, etc., are negligible compared to the acceleration due to the Earth's axial rotation.) Let us now investigate motion in a rotating reference frame.