Edexcel M3 2021 June — Question 7

Exam BoardEdexcel
ModuleM3 (Mechanics 3)
Year2021
SessionJune
TopicSimple Harmonic Motion

7. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{b99b3eb0-9bca-42e3-bea9-3b0454a872db-24_177_876_260_593} \captionsetup{labelformat=empty} \caption{Figure 4}
\end{figure} The fixed points \(A\) and \(B\) are 7 m apart on a smooth horizontal surface.
A light elastic string has natural length 2 m and modulus of elasticity 4 N . One end of the string is attached to a particle \(P\) of mass 2 kg and the other end is attached to \(A\) Another light elastic string has natural length 3 m and modulus of elasticity 2 N . One end of this string is attached to \(P\) and the other end is attached to \(B\) The particle \(P\) rests in equilibrium at the point \(O\), where \(A O B\) is a straight line, as shown in Figure 4.
  1. Show that \(O A = 2.5 \mathrm {~m}\). The particle \(P\) now receives an impulse of magnitude 6Ns in the direction \(O B\)
    1. Show that \(P\) initially moves with simple harmonic motion with centre \(O\)
    2. Determine the amplitude of this simple harmonic motion. The point \(C\) lies on \(O B\). As \(P\) passes through \(C\) the string attached to \(B\) becomes slack.
  2. Find the speed of \(P\) as it passes through \(C\)
  3. Find the time taken for \(P\) to travel directly from \(O\) to \(C\)