Q.Write unit vector in the opposite direction to $\bar u = 8\hat i + 3\hat j - \hat k$.

A scalar quantity is completely described by a magnitude alone (mass, time, temperature), while a vector quantity needs both a magnitude and a direction (displacement, force, velocity) and is drawn as a directed line segment with an initial (tail) point and a terminal (head) point. Around this basic distinction the chapter builds a vocabulary of special vectors: a zero (null) vector has coincident initial and terminal points and no fixed direction; a unit vector has magnitude exactly 1; vectors sharing an initial point are co-initial and vectors sharing a terminal point are co-terminus; two vectors are equal only when they have the same magnitude and the same direction, regardless of where they are drawn; the negative of a vector has the same magnitude but the opposite direction; vectors lying alon …