7.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0e4552e0-7737-439b-a337-789c83c5258c-12_631_1041_242_447}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{figure}
A ball is projected with speed \(40 \mathrm {~ms} ^ { - 1 }\) from a point \(P\) on a cliff above horizontal ground. The point \(O\) on the ground is vertically below \(P\) and \(O P\) is 36 m . The ball is projected at an angle \(\theta ^ { \circ }\) to the horizontal. The point \(Q\) is the highest point of the path of the ball and is 12 m above the level of \(P\). The ball moves freely under gravity and hits the ground at the point \(R\), as shown in Figure 3. Find
- the value of \(\theta\),
- the distance \(O R\),
- the speed of the ball as it hits the ground at \(R\).