A ball is projected vertically upward from the edge of a 25 m high cliff with an initial speed of 20 m/s. Neglect air resistance and take g = 9.8 m/s² acting downward. The ball rises to its highest point, returns past the point of projection, and finally strikes the ground at the foot of the cliff.
Answer the following:
(i) Draw a velocity–time (v–t) graph for the entire motion from the instant of projection until the ball hits the ground. Clearly mark the instants when the ball is momentarily at rest at its highest point and when it passes the projection point on its way down.
(ii) Using the graph, determine the time taken by the ball to reach its highest point.
(iii) Determine the total time of flight until the ball strikes the ground at the foot of the cliff.
(iv) Sketch a qualitative position–time (x–t) graph for the same motion, taking the cliff top as the origin (x = 0). Mark the highest point reached and the point where the ball hits the ground.