| Exam Board | AQA |
|---|---|
| Module | M2 (Mechanics 2) |
| Year | 2016 |
| Session | June |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Centre of Mass 1 |
| Type | L-shaped or composite rectangular lamina |
| Difficulty | Moderate -0.3 This is a standard M2 centre of mass question involving a composite lamina. Part (a) is given, part (b) requires decomposition into rectangles and taking moments (routine calculation), part (c) applies the standard equilibrium condition tan(θ) = horizontal/vertical distance, and part (d) tests understanding. While multi-part with 9 marks total, each step follows textbook methods with no novel problem-solving required, making it slightly easier than average. |
| Spec | 6.04b Find centre of mass: using symmetry6.04e Rigid body equilibrium: coplanar forces |
The diagram shows a uniform lamina $ABCDEFGHIJKL$.
\includegraphics{figure_3}
\begin{enumerate}[label=(\alph*)]
\item Explain why the centre of mass of the lamina is $35$ cm from $AL$.
[1 mark]
\item Find the distance of the centre of mass from $AF$.
[4 marks]
\item The lamina is freely suspended from $A$.
Find the angle between $AB$ and the vertical when the lamina is in equilibrium.
[3 marks]
\item Explain, briefly, how you have used the fact that the lamina is uniform.
[1 mark]
\end{enumerate}
\hfill \mbox{\textit{AQA M2 2016 Q3 [9]}}