SPS SPS FM Mechanics 2021 September — Question 3 9 marks

Exam BoardSPS
ModuleSPS FM Mechanics (SPS FM Mechanics)
Year2021
SessionSeptember
Marks9
TopicForces, equilibrium and resultants
TypeEquilibrium of particle under coplanar forces
DifficultyStandard +0.3 This is a standard statics problem requiring a force diagram and resolution of forces in equilibrium. While it involves three forces and symmetry, the solution is straightforward: resolve vertically to get 2R cos(40°) = 8g, then solve for R. The geometry is given, and the method is a direct application of equilibrium conditions with no novel insight required.
Spec3.03a Force: vector nature and diagrams3.03b Newton's first law: equilibrium3.03e Resolve forces: two dimensions3.03m Equilibrium: sum of resolved forces = 0

A cylindrical object with mass 8 kg rests on two cylindrical bars of equal radius. The lines connecting the centre of each of the bars to the centre of the object make an angle of \(40°\) to the vertical. \includegraphics{figure_2}
  1. Draw a diagram showing all the forces acting on the object. Describe each of the forces using words. [2]
  2. Calculate the magnitude of the force on each of the bars due to the cylindrical object. [7]

A cylindrical object with mass 8 kg rests on two cylindrical bars of equal radius. The lines connecting the centre of each of the bars to the centre of the object make an angle of $40°$ to the vertical.

\includegraphics{figure_2}

\begin{enumerate}[label=(\alph*)]
\item Draw a diagram showing all the forces acting on the object. Describe each of the forces using words. [2]
\item Calculate the magnitude of the force on each of the bars due to the cylindrical object. [7]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM Mechanics 2021 Q3 [9]}}