Vectors

Abstract

If a point moves from P to Q by any path, then the length of the straight line PQ gives the magnitude of the displacement. (This in general will be different from the distance covered in moving from P to Q). This magnitude together with the direction of the straight line from P to Q specifies the vector displacement. It may be written $\overrightarrow {PQ}$ and read as ‘the vector displacement PQ’. $\overrightarrow {QP}$ may be similarly defined and can be seen to have the same magnitude as, but the opposite direction to, $\overrightarrow {PQ}$.