Standard +0.3 This is a straightforward centre of mass problem with two uniform shapes (disc and rectangle) where coordinates are easily determined from the geometry. Students apply the standard formula with given masses and simple position calculations. The multiple-choice format and clear diagram reduce difficulty further, making this slightly easier than average.
3 A uniform disc has mass 6 kg and diameter 8 cm
A uniform rectangular lamina, \(A B C D\), has mass 4 kg , width 8 cm and length 20 cm
The disc is fixed to the lamina to form a composite body as shown in the diagram below.
\includegraphics[max width=\textwidth, alt={}, center]{cd0d239b-ab92-4d17-9cb8-45722e2894cb-03_448_881_587_577}
The sides \(A B , A D\) and \(C D\) are tangents to the disc.
Calculate the distance of the centre of mass of the composite body from \(A D\)
Circle your answer.
4 cm
5.6 cm
6.4 cm
8.8 cm
3 A uniform disc has mass 6 kg and diameter 8 cm
A uniform rectangular lamina, $A B C D$, has mass 4 kg , width 8 cm and length 20 cm\\
The disc is fixed to the lamina to form a composite body as shown in the diagram below.\\
\includegraphics[max width=\textwidth, alt={}, center]{cd0d239b-ab92-4d17-9cb8-45722e2894cb-03_448_881_587_577}
The sides $A B , A D$ and $C D$ are tangents to the disc.\\
Calculate the distance of the centre of mass of the composite body from $A D$\\
Circle your answer.\\
4 cm\\
5.6 cm\\
6.4 cm\\
8.8 cm
\hfill \mbox{\textit{AQA Further Paper 3 Mechanics 2023 Q3 [1]}}