The projection of a vector $\vec r\, = \,3\hat i\, + \,\hat j\, + \,2\hat k$ on the $xy$ plane has magnitude
$3$
$4$
$\sqrt {14} $
$\sqrt {10} $
The magnitude of the $X$ and $Y$ component of $\vec A$ are $7$ and $6$ respectively. Also the magnitude of $X$ and $Y$ component of $\vec A + \vec B$ are $11$ and $9$ respectively. What is the magnitude of $\vec B$ ?
A displacement vector of magnitude $4$ makes an angle $30^{\circ}$ with the $x$-axis. Its rectangular components in $x-y$ plane are .........