7.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{5ef8231d-5b95-4bbb-a8e2-788c708fa078-24_711_1009_251_479}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{figure}
A small ball \(P\) is projected with speed \(15 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) from a point \(A\) which is 47.5 m above a horizontal beach. The ball moves freely under gravity and hits the beach at the point \(B\), as shown in Figure 3.
- By considering energy, find the speed of \(P\) immediately before it hits the beach.
The ball was projected from \(A\) at an angle \(\theta\) above the horizontal, where \(\sin \theta = \frac { 3 } { 5 }\)
- Find the greatest height above the beach of \(P\) as it moved from \(A\) to \(B\).
- Find the least speed of \(P\) as it moved between \(A\) and \(B\).
- Find the horizontal distance from \(A\) to \(B\).