6.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{ba698f74-a51c-409a-a9d9-e9080fc87be2-10_609_1013_118_456}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}

A particle $P$ of mass 4 kg is held at rest at the point $A$ on a rough plane which is inclined at $30 ^ { \circ }$ to the horizontal. The point $B$ lies on the line of greatest slope of the plane that passes through $A$. The point $B$ is 5 m down the plane from $A$, as shown in Figure 3. The coefficient of friction between the plane and $P$ is 0.3

The particle is released from rest at $A$ and slides down the plane.
\begin{enumerate}[label=(\alph*)]
\item Find the speed of $P$ at the instant it reaches $B$.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{ba698f74-a51c-409a-a9d9-e9080fc87be2-10_478_1011_1343_456}
\captionsetup{labelformat=empty}
\caption{Figure 4}
\end{center}
\end{figure}

The particle is now returned to $A$ and is held in equilibrium by a horizontal force of magnitude $H$ newtons, as shown in Figure 4. The line of action of the force lies in the vertical plane containing the line of greatest slope of the plane through $A$. The particle is on the point of moving up the plane.
\item Find the value of $H$.
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2017 Q6 [14]}}