6.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{151d9232-5a78-4bc1-a57e-6c9cae80e473-22_428_993_251_479}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{figure}
A small ball is thrown vertically upwards at time \(t = 0\) from a point \(A\) which is above horizontal ground. The ball hits the ground 7 s later.
The ball is modelled as a particle moving freely under gravity.
The velocity-time graph shown in Figure 3 represents the motion of the ball for \(0 \leqslant t \leqslant 7\)
- Find the speed with which the ball is thrown.
- Find the height of \(A\) above the ground.