If $\left| {{{\vec v}_1} + {{\vec v}_2}} \right| = \left| {{{\vec v}_1} - {{\vec v}_2}} \right|$ and ${{{\vec v}_1}}$ and ${{{\vec v}_2}}$ are finite, then
${{{\vec v}_1}}$ is parallel to ${{{\vec v}_2}}$
${{{\vec v}_1} = {{\vec v}_2}}$
$\left| {{{\vec v}_1}} \right| = \left| {{{\vec v}_2}} \right|$
${{{\vec v}_1}}$ and ${{{\vec v}_2}}$ are mutually perpendicular
If $\vec{P}+\vec{Q}=\vec{P}-\vec{Q}$, then
Which of the following forces cannot be a resultant of $5\, N$ and $7\, N$ force...........$N$
Two vectors $\vec A$ and $\vec B$ have magnitudes $2$ and $1$ respectively. If the angle between $\vec A$ and $\vec B$ is $60^o$, then which of the following vectors may be equal to $\frac{{\vec A}}{2} - \vec B$