181. In the figure below, the electric field vector at the vertex of an equilateral triangle in SI units is $\vec{E} = -2\times10^5\,\hat{i} - 1.8\times10^5\,\hat{j}$. The charges $q_1$ and $q_2$ are respectively how many microcoulombs? $\left(k = 9\times10^9\,\dfrac{\text{N}\cdot\text{m}^2}{\text{C}^2}\right)$ [Figure: Equilateral triangle with side 90 cm and height 40 cm; charge $q_1$ at top-right vertex, charge $q_2$ at bottom-left vertex, coordinate axes at bottom-right vertex]
[(1)] $-4.8$ and $-6$
[(2)] $4.8$ and $-6$
[(3)] $-8$ and $-12.8$
[(4)] $+8$ and $-12.8$
\textbf{181.} In the figure below, the electric field vector at the vertex of an equilateral triangle in SI units is $\vec{E} = -2\times10^5\,\hat{i} - 1.8\times10^5\,\hat{j}$. The charges $q_1$ and $q_2$ are respectively how many microcoulombs? $\left(k = 9\times10^9\,\dfrac{\text{N}\cdot\text{m}^2}{\text{C}^2}\right)$
\textit{[Figure: Equilateral triangle with side 90 cm and height 40 cm; charge $q_1$ at top-right vertex, charge $q_2$ at bottom-left vertex, coordinate axes at bottom-right vertex]}
\begin{itemize}
\item[(1)] $-4.8$ and $-6$
\item[(2)] $4.8$ and $-6$
\item[(3)] $-8$ and $-12.8$
\item[(4)] $+8$ and $-12.8$
\end{itemize}
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