Answer the following with reference to the motion of bodies undergoing free fall near the Earth’s surface.
(i) Define free fall.
(ii) List the three standard relations connecting displacement, velocity and time for a body falling vertically when the downward direction is chosen as positive.
(iii) If a ball is projected vertically upward but the upward direction is taken as positive, explain whether the acceleration due to gravity should be written as positive or negative. Give reason.
(iv) A student claims that the numerical value of the distance travelled by a stone in free fall during the first 5 s is the same as its displacement in that interval. Comment on the correctness of this statement, giving justification.