ABSTRACT
This chapter gives sound introduction to the manipulation and use of scalars and vectors, by both graphical and analytical methods. In this chapter the fundamental quantities, scalars and vectors, which form the very basis of all branches of engineering, are introduced. Force is a vector quantity and thus has both a magnitude and a direction. An object is in equilibrium when the forces acting on the object are such that there is no tendency for the object to move. When forces are all acting in the same plane, they are called coplanar. Calculation of determining the resultant of two coplanar forces can be achieved by trigonometry using the cosine rule and the sine rule. When three or more coplanar forces are acting at a point and the vector diagram closes, there is no resultant. The forces acting at the point are in equilibrium. When forces act at the same time and at the same point, they are called concurrent forces.
