- #1

- 1,752

- 143

Let's just concentrate on the cube's left face. From class notes [tex]\Phi _{{\rm{left}}} = \left\langle {\overrightarrow E \cdot {\rm{\hat n}}} \right\rangle {\rm{ Area}}[/tex]

[tex]\begin{array}{l}

\Phi _{{\rm{left}}} = \left\langle {\overrightarrow E \cdot {\rm{\hat n}}} \right\rangle {\rm{ Area = }}\left( {15{\rm{ N/C}} \cdot 1} \right){\rm{ + }}\left( {{\rm{27 N/C}} \cdot 0} \right){\rm{ + }}\left( {{\rm{39 N/C}} \cdot 0} \right)\left( {2{\rm{m}}} \right)^2 {\rm{ = }}\left( {15{\rm{ N/C}}} \right){\rm{ + }}\left( 0 \right){\rm{ + }}\left( 0 \right)\left( {2{\rm{m}}} \right)^2 = \\

\\

\left( {15{\rm{ N/C}}} \right)4{\rm{m}}^2 = 60{\rm{Nm}}^{\rm{2}} /{\rm{C}} \\

\end{array}[/tex]

But the units are wrong. Shouldn't they be C/m

^{2}?