A stone is projected vertically upward from ground level with an initial speed of 20ms−1. Ignore air resistance.
(i) Calculate the maximum height reached by the stone and the total time it remains in air before returning to the projection point.
(ii) Draw a carefully labelled velocity–time graph for the entire motion from launch until the stone returns to ground level. Indicate numerical values of velocity at key instants and mark the time axis intercepts.
(iii) Using the area enclosed by the velocity–time graph, verify quantitatively that the net displacement of the stone over the complete flight is zero.
(iv) Sketch the corresponding position–time graph on the same time scale, showing clearly the curvature and the point of maximum height.