OCR MEI M1 2016 June — Question 5

Exam BoardOCR MEI
ModuleM1 (Mechanics 1)
Year2016
SessionJune
TopicSUVAT in 2D & Gravity

5 Mr McGregor is a keen vegetable gardener. A pigeon that eats his vegetables is his great enemy.
One day he sees the pigeon sitting on a small branch of a tree. He takes a stone from the ground and throws it. The trajectory of the stone is in a vertical plane that contains the pigeon. The same vertical plane intersects the window of his house. The situation is illustrated in Fig. 5. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{4c8c96cf-5184-46e4-9c45-a8a80d0a6ff8-4_400_1221_1078_411} \captionsetup{labelformat=empty} \caption{Fig. 5}
\end{figure}
  • The stone is thrown from point O on level ground. Its initial velocity is \(15 \mathrm {~ms} ^ { - 1 }\) in the horizontal direction and \(8 \mathrm {~ms} ^ { - 1 }\) in the vertical direction.
  • The pigeon is at point P which is 4 m above the ground.
  • The house is 22.5 m from O .
  • The bottom of the window is 0.8 m above the ground and the window is 1.2 m high.
Show that the stone does not reach the height of the pigeon. Determine whether the stone hits the window.