The unit vector is given by $a\hat{i} + b\hat{j} + c\hat{k}$. If the values of $a$ and $b$ are $0.6$ and $0.8$ respectively,find the value of $c$.

$ABCDEF$ is a regular hexagon and forces represented in magnitude and direction by $\overrightarrow{AB}, \overrightarrow{AC}, \overrightarrow{AD}, \overrightarrow{AE}$ and $\overrightarrow{AF}$ act at point $A$. Their resultant is:

$A$ vector $\overrightarrow{a}$ is turned without a change in its length through a small angle $d\theta$. The values of $|\Delta \overrightarrow{a}|$ and $\Delta a$ are respectively:

$A$ particle has a displacement of $12 \, m$ towards east,$5 \, m$ towards north,and $6 \, m$ vertically upward. The magnitude of the resultant displacement is ......... $m$.

The angle made by a vector $\vec{B} = 3 \hat{i} + 2 \hat{j} + 4 \hat{k}$ with the $y$-axis is:

The vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ lie in a plane. Another vector $\overrightarrow{C}$ lies outside this plane. The resultant $\overrightarrow{R} = \overrightarrow{A} + \overrightarrow{B} + \overrightarrow{C}$ of these three vectors: