SPS SPS SM Pure 2023 June — Question 10

Exam BoardSPS
ModuleSPS SM Pure (SPS SM Pure)
Year2023
SessionJune
TopicQuadratic Functions

10. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{f953fd1c-447f-4e97-a42a-5264c053fda0-20_424_1241_246_299} \captionsetup{labelformat=empty} \caption{Figure 5}
\end{figure} \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{f953fd1c-447f-4e97-a42a-5264c053fda0-20_385_1205_792_379} \captionsetup{labelformat=empty} \caption{Figure 6}
\end{figure} A suspension bridge cable \(P Q R\) hangs between the tops of two vertical towers, \(A P\) and \(B R\), as shown in Figure 5. A walkway \(A O B\) runs between the bases of the towers, directly under the cable.
The towers are 100 m apart and each tower is 24 m high.
At the point \(O\), midway between the towers, the cable is 4 m above the walkway.
The points \(P , Q , R , A , O\) and \(B\) are assumed to lie in the same vertical plane and \(A O B\) is assumed to be horizontal. Figure 6 shows a symmetric quadratic curve \(P Q R\) used to model this cable.
Given that \(O\) is the origin,
  1. find an equation for the curve \(P Q R\). Lee can safely inspect the cable up to a height of 12 m above the walkway.
    A defect is reported on the cable at a location 19 m horizontally from one of the towers.
  2. Determine whether, according to the model, Lee can safely inspect this defect.