Question

A vector is represented by $3\hat{i}+\hat{j}+2\hat{k}$. Projection of this vector in $XY$ plane is

Answer 1

Answer: 3.16

$\vec{R}=3\hat{i}+\hat{j}+2\hat{k}$
$\therefore$ Length in $XY$ plane $=\sqrt{R_x^2+R_y^2}$
$=\sqrt{3^2+1^2}=\sqrt{10}$