OCR MEI M3 2013 January — Question 3

Exam BoardOCR MEI
ModuleM3 (Mechanics 3)
Year2013
SessionJanuary
TopicWork, energy and Power 2

3 Two fixed points X and Y are 14.4 m apart and XY is horizontal. The midpoint of XY is M . A particle P is connected to X and to Y by two light elastic strings. Each string has natural length 6.4 m and modulus of elasticity 728 N . The particle P is in equilibrium when it is 3 m vertically below M, as shown in Fig. 3. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{3f674569-7e99-4ba8-84f1-a1eb438e30ed-3_284_878_404_580} \captionsetup{labelformat=empty} \caption{Fig. 3}
\end{figure}
  1. Find the tension in each string when P is in the equilibrium position.
  2. Show that the mass of P is 12.5 kg . The particle P is released from rest at M , and moves in a vertical line.
  3. Find the acceleration of P when it is 2.1 m vertically below M .
  4. Explain why the maximum speed of P occurs at the equilibrium position.
  5. Find the maximum speed of P .