Two stones are thrown simultaneously from the edge of a cliff \(240~\text{m}\) high. The first stone is thrown upward with an initial speed of \(10~\text{m/s},\) and the second with \(40~\text{m/s}.\) Assuming the stones do not bounce after hitting the ground and neglecting air resistance (\(g= 10~\text{m/s}^2\)), which of the following graphs best represents how the position of the second stone varies relative to the first stone with time? (graphs are schematic and not drawn to scale)

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Train \(\mathrm{A}\) and Train \(\mathrm{B}\) are running on parallel tracks in opposite directions with speeds of \(36~\text{km/h}\) and \(72~\text{km/h},\) respectively. A person is walking inside Train \(\mathrm{A}\) in the direction opposite to the train's motion with a speed of \(1.8~\text{km/h} .\) What is the speed of this person as observed from Train \(\mathrm{B}\)? (Assume the distance between the tracks is negligible.)