| Exam Board | Edexcel |
|---|---|
| Module | M2 (Mechanics 2) |
| Year | 2003 |
| Session | January |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Centre of Mass 1 |
| Type | Particles at coordinate positions |
| Difficulty | Moderate -0.8 This is a straightforward centre of mass calculation requiring direct application of the standard formula. Part (a) uses the x-coordinate equation to find λ (simple algebra), and part (b) substitutes to find k using the y-coordinate equation. It's routine bookwork with no problem-solving insight needed, making it easier than average but not trivial since it requires careful algebraic manipulation across two parts. |
| Spec | 6.04b Find centre of mass: using symmetry |
Three particles of mass $3m$, $5m$ and $\lambda m$ are placed at points with coordinates $(4, 0)$, $(0, -3)$ and $(4, 2)$ respectively. The centre of mass of the system of three particles is at $(2, k)$.
\begin{enumerate}[label=(\alph*)]
\item Show that $\lambda = 2$. [4]
\item Calculate the value of $k$. [3]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M2 2003 Q1 [7]}}