5.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{99d06f7b-f5cc-4c19-ae26-8f715eda8ee8-16_419_531_214_708}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}

Figure 3 shows a uniform rectangular lamina $A B C D$ with sides of length $3 a$ and $k a$, where $k > 3$. The point $E$ on side $A D$ is such that $D E = 3 a$. Rectangle $A B C D$ is folded along the line $C E$ to produce the folded lamina $L$ shown in Figure 4.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{99d06f7b-f5cc-4c19-ae26-8f715eda8ee8-16_455_536_941_703}
\captionsetup{labelformat=empty}
\caption{Figure 4}
\end{center}
\end{figure}

Find, in terms of $a$ and $k$,
\begin{enumerate}[label=(\alph*)]
\item the distance of the centre of mass of $L$ from $A B$,
\item the distance of the centre of mass of $L$ from $A E$.

The folded lamina $L$ is freely suspended from $A$ and hangs in equilibrium with $A B$ at $45 ^ { \circ }$ to the downward vertical.
\item Find, to 3 significant figures, the value of $k$.

\begin{center}

\end{center}
\end{enumerate}

\hfill \mbox{\textit{Edexcel M2 2018 Q5 [13]}}