8.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{6978be48-561b-49a0-a297-c8886ca66c19-20_312_1068_230_438}
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\caption{Figure 3}
\end{center}
\end{figure}

Two particles $P$ and $Q$ have masses 2 kg and 3 kg respectively. The particles are attached to the ends of a light inextensible string. The string passes over a smooth light pulley which is fixed at the top of a rough plane. The plane is inclined to horizontal ground at an angle $\alpha$, where tan $\alpha = \frac { 3 } { 4 }$. Initially $P$ is held at rest on the inclined plane with the part of the string from $P$ to the pulley parallel to a line of greatest slope of the plane. The particle $Q$ hangs freely below the pulley at a height of 0.5 m above the ground, as shown in Figure 3. The coefficient of friction between $P$ and the plane is $\mu$. The system is released from rest, with the string taut, and $Q$ strikes the ground before $P$ reaches the pulley. The speed of $Q$ at the instant when it strikes the ground is $1.4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$.
\begin{enumerate}[label=(\alph*)]
\item For the motion before $Q$ strikes the ground, find the tension in the string.
\item Find the value of $\mu$.

\begin{center}
\begin{tabular}{|l|l|}
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\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2016 Q8 [13]}}