A rubber ball falls freely from a height h onto a smooth floor. After striking the floor, the ball again rises to the same height. Assume that the duration of contact of the ball with the floor is negligible. Identify the correct graph for velocity with time and height with time.

1.

2.

3.

4.

3.

Reason —

Option (1) :

Velocity graph is incorrect as it always shows positive velocity and height graph is also incorrect because it shows that height of ball was zero for some amount of time whereas in the question it is mentioned that ball was in contact with floor for negligible time.

Option (2) :

Velocity graph is incorrect because it's linear sections with sign reversal is not following height-time graph but height graph is correct as it is smooth parabolic curves representing motion to and from height h.

Option (3) :

Velocity graph is correct because it's linear sections with sign reversal is following height-time graph and height-time graph is also correct as it is smooth parabolic curves representing motion to and from height h.

Option (4) :

Velocity graph is incorrect because the process of sign reversal of velocity should be instantaneous and have no time gap during sign reversal. Height graph is also incorrect as it shows the ball has started it's motion from ground (h = 0) which is not the case as the ball is released from a particular height.