A pebble is released from rest from the edge of a cliff that is 80 m high.
a. (i) Calculate the time taken by the pebble to reach the foot of the cliff.
b. (ii) Determine the magnitude of its velocity just before it strikes the ground.
c. (iii) Sketch a velocity–time graph for the entire motion and state what the slope of the graph and the area under the graph represent in this context.