Two stones are thrown vertically up with initial velocity Vo, second stone with a time delay To with respect to the first one. At which time after the beginning of the motion the two stones will collide? Is this scenario possible for any Vo and To? What are the limitations?

Answer 1

well, you cant let To be greater than the time for the first stone to fall....

first stone: Vo*t-1/2 g To
second stone: Vo*(t-To)-1/2 g (t-To)

those are the heights. Set them equal, and find t.

Answer 2

what do you mean by "set them equal"?