(i) Define free fall.
(ii) An object is released from rest and its velocity is recorded at equal time intervals as it falls straight down. Sketch the expected velocity–time graph for this motion and describe its general shape.
(iii) Explain clearly what physical quantity is represented by the slope of the velocity–time graph drawn in part (ii).
(iv) Give a reasoned argument to show why measuring this slope provides a method for determining the numerical value of the acceleration due to gravity near the Earth’s surface.