I am in an introductory physics class and doing one of these problems, and though it probably isn't too difficult it has stumped me, mainly due to the fact that it asks for vi instead of d or something like that. Anyway, I'm just going to paraphrase the question: Suppose a basketball player 2.45 m tall throws a basketball at that height and it lands with a speed of 12.0 m/s. What is the ball's initial speed? The equations you might have to use are simple DVAT's: df=di+vit+.5at^2 vf=vi+at These 2 primarily. So, d=-2.45 vf=12.0 m/s (I think?) a=-9.80 m/s^2 From this I got t=.707 s, and I think I should be able to get the vi in the next step or two, but I can't figure out what those steps are. Help please?