Question

A ball is dropped from a height of 19.6 m above the ground. It rebounds from the ground and raises itself up to the same height. Take the starting point as the origin and vertically downward as the positive X-axis. Draw approximate plots of x versus t, v versus t and a versus t. Neglect the small interval during which the ball was in contact with ground. 

Answer 1

 Lets take downward as positive a(t)=g

Time of ascent ( t₂) = time of decent (t₁)

The motion of ball is symmetric about t=2 i.e., if we make t=4 as initial point, and reverse the motion of time ascent looks like decent.