Edexcel M3 2005 January — Question 3

Exam BoardEdexcel
ModuleM3 (Mechanics 3)
Year2005
SessionJanuary
TopicCentre of Mass 2

3. \begin{figure}[h]
\captionsetup{labelformat=empty} \caption{Figure 2} \includegraphics[alt={},max width=\textwidth]{51510155-a8cc-4e70-8ffa-44ed35618261-3_531_899_299_497}
\end{figure} A uniform lamina occupies the region \(R\) bounded by the \(x\)-axis and the curve $$y = \sin x , \quad 0 \leq x \leq \pi$$ as shown in Figure 2.
  1. Show, by integration, that the \(y\)-coordinate of the centre of mass of the lamina is \(\frac { \pi } { 8 }\). \begin{figure}[h]
    \captionsetup{labelformat=empty} \caption{Figure 3} \includegraphics[alt={},max width=\textwidth]{51510155-a8cc-4e70-8ffa-44ed35618261-3_652_792_1439_568}
    \end{figure} A uniform prism \(S\) has cross-section \(R\). The prism is placed with its rectangular face on a table which is inclined at an angle \(\theta ^ { \circ }\) to the horizontal. The cross-section \(R\) lies in a vertical plane as shown in Figure 3. The table is sufficiently rough to prevent \(S\) sliding. Given that \(S\) does not topple,
  2. find the largest possible value of \(\theta\).
    (3)