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

The resultant of $\overrightarrow A + \overrightarrow B $ is ${\overrightarrow R _1}.$ On reversing the vector $\overrightarrow {B,} $ the resultant becomes ${\overrightarrow R _2}.$ What is the value of $R_1^2 + R_2^2$

Two forces having magnitude $A$ and $\frac{ A }{2}$ are perpendicular to each other. The magnitude of their resultant is

If the resultant of $n$ forces of different magnitudes acting at a point is zero, then the minimum value of $n$ is

When $n$ vectors of different magnitudes are added, we get a null vector. Then the value of $n$ cannot be

The magnitudes of vectors $\vec A,\,\vec B$ and $\vec C$ are $3, 4$ and $5$ units respectively. If $\vec A + \vec B = \vec C$, the angle between $\vec A$ and $\vec B$ is