The ratio of maximum and minimum magnitudes of the resultant of two vector $\vec a$ and $\vec b$ is $3 : 1$. Now $| \vec a |$  is equal to

A hall has the dimensions $10\,m \times 12\,m \times 14\,m.$A fly starting at one corner ends up at a diametrically opposite corner. What is the magnitude of its displacement...........$m$

Find unit vector perpendicular to $\vec A$ and $\vec B$ where $\vec A = \hat i - 2\hat j + \hat k$ and $\vec B = \hat i + 2\hat j$

$\overrightarrow{ A }=4 \hat{ i }+3 \hat{ j }$ and $\overrightarrow{ B }=4 \hat{ i }+2 \hat{ j }$. Find a vector parallel to $\overrightarrow{ A }$ but has magnitude five times that of $\vec{B}$.

A particle has displacement of $12 \,m$ towards east and $5 \,m$ towards north then $6 \,m $ vertically upward. The sum of these displacements is........$m$

The position vectors of points $A, B, C$ and $D$ are $\vec A = 3\hat i + 4\hat j + 5\hat k,\,\vec B = 4\hat i + 5\hat j + 6\hat k,\,\vec C = 7\hat i + 9\hat j + 3\hat k$ and $\vec D = 4\hat i + 6\hat j$ then the displacement vectors $\overrightarrow {AB} $ and $\overrightarrow {CD} $ are