Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
The diagram represents a circular shape assembled from a uniform semicircular lamina of weight $11\,\mathrm{N}$ together with a uniform semicircular arc of weight $9\,\mathrm{N}$. Both parts have centre $O$ and radius $0.7\,\mathrm{m}$, and they are connected at the endpoints of their shared diameter $AB$.
(i)[3]
Demonstrate that the distance from $O$ to the centre of mass of the object is $0.0371\,\mathrm{m}$, correct to $3$ significant figures.
(ii)[3]
Find the angle between $AB$ and the vertical, and indicate whether the object’s lowest point is on the lamina or on the arc.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Table-of-values method used with the correct signs for $(9+11)OG = +[-9 \times 0.7/(\pi/2) - 11 \times (2 \times 0.7)/3\pi/2]” …