2.3 Exercise 16

At one point in space, the direction of the electric field vector is given in the Cartesian system by the unit vector $\hat{E} = 1 / \sqrt{5} \hat{i} - 2 / \sqrt{5} \hat{j}$. If the magnitude of the electric field vector is E = 400.0 V/m, what are the scalar components $E_{x}$, $E_{y}$, and $E_{z}$ of the electric field vector $\overset{\rightarrow}{E}$ at this point? What is the direction angle $\theta_{E}$ of the electric field vector at this point?