Edexcel M1 — Question 2

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
TopicMoments

  1. Find the speed of \(B\).
  2. Find the velocity of \(B\) relative to \(A\).
  3. Find the acute angle between the relative velocity found in part (b) and the vector \(\mathbf { i }\), giving your answer in degrees correct to 1 decimal place.
    (2 marks) \item \end{enumerate} \begin{figure}[h]
    \includegraphics[alt={},max width=\textwidth]{2108a1be-0214-42c4-9cb4-8622cc0fa496-2_360_1018_1242_479} \captionsetup{labelformat=empty} \caption{Fig. 1}
    \end{figure} Figure 1 shows a uniform plank \(A B\) of length 8 m and mass 30 kg . It is supported in a horizontal position by two pivots, one situated at \(A\) and the other 2 m from \(B\). A man whose mass is 80 kg is standing on the plank 2 m from \(A\) when his dog steps onto the plank at \(B\). Given that the plank remains in equilibrium and that the magnitude of the forces exerted by each of the pivots on the plank are equal,
  4. calculate the magnitude of the force exerted on the plank by the pivot at \(A\),
  5. find the dog's mass. If the dog was heavier and the plank was on the point of tilting,
  6. explain how the force exerted on the plank by each of the pivots would be changed.
    (2 marks)