As we have seen in Chapter 3, the direction and speed of movement of a plate is determined by the initial imbalance between the driving and the retarding forces. The driving force gives rise to acceleration of the plate. Such acceleration induces viscous drag on the LVZ, so that at a specific rate of movement of the plate, the forces come into balance and the plate, thereafter, moves at a constant rate until some major disturbing effect comes into play. From the size, geometry and rates of motion of the plates, one can infer that normal plate motion can only be expected to change very, very slowly. Hence, it is logical to infer that, if a plate experiences sudden acceleration or deceleration and/or change of direction, a major change must have abruptly taken place in one or more of the boundary force conditions. Indeed, in order that the inertia of these immensely heavy plates can be rapidly overcome, one must postulate the action of an immensely powerful mechanism.
Was this article helpful?