A scalar quantity is one that is dimensionless in terms of direction and is expressed in terms that communicate their magnitude. Energy and time are two great examples of such. On the other hand, there are vectors. Unlike scalar quantities, vectors possess both magnitude and direction.
For example, an object can be considered to travel along the positive x-axis with a constant velocity ( v ). If the object began traveling in the opposite direction, this would be quantified with a ( – v ) designation. Furthermore, vectors can exist two-dimensionally off of the x/y-axis as follows:
These vectors have been added to one another via alignment from tip-to-tail. If each vector was expressed in terms of their ( x ) and ( y ) components, subsequent addition of the components would give us the value expressed at the end of vector C. If we wanted instead to subtract B from C, we’d simply reverse the direction of vector B:
Vector addition can indeed be challenging, but the task of adding vectors can be simplified with the usage of angles that each vector has in common with the x-axis. When this is the case, familiar trigonometry functions are used to break vectors into their respective components.
RENAISSANCE PHYSICS 