OCR
Further Pure Core 1
2021
November
Q6
3 marks
Standard +0.8
\(O\) is the origin of a coordinate system whose units are cm. The points \(A\), \(B\), \(C\) and \(D\) have coordinates \((1, 0)\), \((1, 4)\), \((6, 9)\) and \((0, 9)\) respectively.
The arc \(BC\) is part of the curve with equation \(x^2 + (y - 10)^2 = 37\).
The closed shape \(OABCD\) is formed, in turn, from the line segments \(OA\) and \(AB\), the arc \(BC\) and the line segments \(CD\) and \(DO\) (see diagram).
A funnel can be modelled by rotating \(OABCD\) by \(2\pi\) radians about the \(y\)-axis.
\includegraphics{figure_6}
Find the volume of the funnel according to the model. [3]