Edexcel M3 2017 June — Question 6

Exam BoardEdexcel
ModuleM3 (Mechanics 3)
Year2017
SessionJune
TopicWork, energy and Power 2

  1. The ends of a light elastic string, of natural length 0.4 m and modulus of elasticity \(\lambda\) newtons, are attached to two fixed points \(A\) and \(B\) which are 0.6 m apart on a smooth horizontal table. The tension in the string is 8 N .
    1. Show that \(\lambda = 16\)
    A particle \(P\) is attached to the midpoint of the string. The particle \(P\) is now pulled horizontally in a direction perpendicular to \(A B\) to a point 0.4 m from the midpoint of \(A B\). The particle is held at rest by a horizontal force of magnitude \(F\) newtons acting in a direction perpendicular to \(A B\), as shown in Figure 5 below. \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{698b44b5-801c-45ec-b9de-021e44487edb-18_623_796_792_573} \captionsetup{labelformat=empty} \caption{Figure 5}
    \end{figure}
  2. Find the value of \(F\). The particle is released from rest. Given that the mass of \(P\) is 0.3 kg ,
  3. find the speed of \(P\) as it crosses the line \(A B\).