Page 31 - eEISBN FINALIZE

2.5.1 SCALAR NOTATION

Axes x and y in figure has been designated positive and negative direction. Therefore, the
magnitude and directional sense of the rectangular components of a force can be expressed in term

of algebraic scalars.

So the first situation the components of F can be represented by two positive scalars, Fx and Fy
since their sense of direction is along the positive axes. Meanwhile the second situation show the

component of F’ can represented by Fx’ and – Fy’. The symbol negative show that the component

Fy’ is directed along the negative y axis.

Figure 2.17: Resultant Force, F’

It is important to bear in mind that this scalar notation is to be used for computational purpose

only, not for graphical representation in figure. The arrow head of the vector in any figure indicates

the sense of the vector graphically and algebraic signs are not used for this purpose.

2.5.2 CARTESIAN VECTOR NOTATION

Two vectors of unit magnitude will be introduced at this point. These two unit vectors are called

CARTESIAN unit vectors i and j. Both of them are directed along the x and y axes respectively.
These vectors are called unit vectors and are denoted by i and j respectively as shown in figure

below

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