Edexcel M1 2018 June — Question 7 12 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2018
SessionJune
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMoments
TypeParticle suspended by strings
DifficultyModerate -0.3 This is a standard M1 equilibrium problem requiring resolution of forces at two particles. Students must resolve forces at B and C using given angles (with tan values provided to simplify calculations), then solve simultaneous equations. While it involves multiple steps and two particles, the setup is straightforward with no geometric complications, making it slightly easier than average for M1.
Spec3.03n Equilibrium in 2D: particle under forces3.04a Calculate moments: about a point3.04b Equilibrium: zero resultant moment and force

7. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{c0993853-dd8f-4d14-aeed-b71ad60df09c-24_206_1040_356_443} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} A washing line \(A B C D\) is fixed at the points \(A\) and \(D\). There are two heavy items of clothing hanging on the washing line, one fixed at \(B\) and the other fixed at \(C\). The washing line is modelled as a light inextensible string, the item at \(B\) is modelled as a particle of mass 3 kg and the item at \(C\) is modelled as a particle of mass \(M \mathrm {~kg}\). The section \(A B\) makes an angle \(\alpha\) with the horizontal, where \(\tan \alpha = \frac { 3 } { 4 }\), the section \(B C\) is horizontal and the section \(C D\) makes an angle \(\beta\) with the horizontal, where \(\tan \beta = \frac { 12 } { 5 }\), as shown in Figure 2. The system is in equilibrium.
  1. Find the tension in \(A B\).
  2. Find the tension in BC.
  3. Find the value of \(M\).
    END

7.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{c0993853-dd8f-4d14-aeed-b71ad60df09c-24_206_1040_356_443}
\captionsetup{labelformat=empty}
\caption{Figure 2}
\end{center}
\end{figure}

A washing line $A B C D$ is fixed at the points $A$ and $D$. There are two heavy items of clothing hanging on the washing line, one fixed at $B$ and the other fixed at $C$. The washing line is modelled as a light inextensible string, the item at $B$ is modelled as a particle of mass 3 kg and the item at $C$ is modelled as a particle of mass $M \mathrm {~kg}$. The section $A B$ makes an angle $\alpha$ with the horizontal, where $\tan \alpha = \frac { 3 } { 4 }$, the section $B C$ is horizontal and the section $C D$ makes an angle $\beta$ with the horizontal, where $\tan \beta = \frac { 12 } { 5 }$, as shown in Figure 2. The system is in equilibrium.
\begin{enumerate}[label=(\alph*)]
\item Find the tension in $A B$.
\item Find the tension in BC.
\item Find the value of $M$.\\

\begin{center}
\begin{tabular}{|l|l|}
\hline

\hline
END &  \\
\hline
\end{tabular}
\end{center}
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2018 Q7 [12]}}