In a vertical jump shown below, there is a velocity versus time graph.

a$)$ ? Where is the person jumping in the air? How do you know this? 

b$)$ ? If the time between each tick in the graph is $0\mathrm{.}1$sec and when the jumper leaves the ground, the time on the graph is $0,$ ?what is the acceleration from the time he is in the air? 

c$)$ ? What do the other portions of the graph represent? 

d$)$ ? What are the two average accelerations before he leaves the ground and what is happening in these sections in his jump?

velocity (m/s) 3.0 0.0 -3.0 time (s) bo