Easy -1.8 This is a straightforward one-mark multiple-choice question requiring only direct application of the centre of mass formula with three particles on a line. The setup is simple, calculations are minimal, and the multiple-choice format removes any need for problem-solving or extended working—significantly easier than typical A-level questions.
3 Three particles are attached to a light rod, \(A B\), of length 40 cm
The particles are attached at \(A , B\) and the midpoint of the rod.
The particle at \(A\) has mass 5 kg
The particle at \(B\) has mass 1 kg
The particle at the midpoint has mass 4 kg
Find the distance of the centre of mass of this system from the midpoint of the rod.
Circle your answer. [0pt]
[1 mark]
\(4 \mathrm {~cm} \quad 8 \mathrm {~cm} \quad 12 \mathrm {~cm} \quad 28 \mathrm {~cm}\)
Turn over for the next question
3 Three particles are attached to a light rod, $A B$, of length 40 cm
The particles are attached at $A , B$ and the midpoint of the rod.\\
The particle at $A$ has mass 5 kg\\
The particle at $B$ has mass 1 kg\\
The particle at the midpoint has mass 4 kg\\
Find the distance of the centre of mass of this system from the midpoint of the rod.\\
Circle your answer.\\[0pt]
[1 mark]\\
$4 \mathrm {~cm} \quad 8 \mathrm {~cm} \quad 12 \mathrm {~cm} \quad 28 \mathrm {~cm}$
Turn over for the next question
\hfill \mbox{\textit{AQA Further Paper 3 Mechanics 2022 Q3 [1]}}