ABSTRACT
Any exertion such as a push or a pull is a force, and this force will have magnitude and will be exerted in some direction. The magnitude or amount of the force may be represented by a straight line drawn to a convenient scale say 10 lb = 1 in. Such lines are shown in Fig. 8.1. In Fig. 8.1, the lines are represented by their lengths of forces mark; they are also shown by their position of the directions of the force. But none of the lines tell us the sense of the direction of the force; it means we do not know whether the force is from A to B or from B to A.
