6.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{778a0276-6738-40e6-90b2-a536ce5abe6a-10_447_908_205_516}
\captionsetup{labelformat=empty}
\caption{Figure 4}
\end{figure}
A golf ball \(P\) is projected with speed \(35 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) from a point \(A\) on a cliff above horizontal ground. The angle of projection is \(\alpha\) to the horizontal, where \(\tan \alpha = \frac { 4 } { 3 }\). The ball moves freely under gravity and hits the ground at the point \(B\), as shown in Figure 4.
- Find the greatest height of \(P\) above the level of \(A\).
The horizontal distance from \(A\) to \(B\) is 168 m .
- Find the height of \(A\) above the ground.
By considering energy, or otherwise,
- find the speed of \(P\) as it hits the ground at \(B\).