bagem, its been a while since my calc based physics classes, but are you seperating horizontal and vertical initial velocities into 2 vectors before doing your math? and since there is a horizontal acceleration of 0 and a veritcal acceleration of 9.8m/s2 -no matter which direction you fire the arrow - i'm not getting how gravity affects poidifferently no matter which way you fire the arrow. the arrow is still shot with an initial vertical and horizontal velocity since the sight pin and the arrow are not on the same, um, what do you call it? line? and gravity does not affect horizontal velocity at all. anyway, i'm curious to the answer, and if i can still understand it. sylvan - where are you?