Find the vertical displacement

[reesejm]

Two basketball players are essentially equal in all respects. (They are the same height, they jump with the same initial velocity, etc.) In particular, by jumping they can raise their centers of mass the same vertical distance, H(called their "vertical leap"). The first player, Arabella, wishes to shoot over the second player, Boris, and for this she needs to be as high above Boris as possible. Arabella jumps at time t=0, and Boris jumps later, at time tr (his reaction time). Assume that Arabella has not yet reached her maximum height when Boris jumps.

Find the vertical displacement D(t) between the raised hands of Arabella and those of Boris as a function of time for the interval 0<t<tr.
Express the vertical displacement in terms ofH ,G , and t.

I have tried many solutions and none seem to be working

 

[stunner5000pt]

Is arabella at a certain height at time T =0 or is that when she jumps off the ground??

 

[poolwin2001]

In case of gravity $v^2=u^2-2gs$.
I hope you know what v,u,g stands for.
You have to assume that both the players have arms in the same position.

 

[reesejm]

arabella leaves the groud at time t=0