1. The problem statement, all variables and given/known data Starting from the constant-acceleration kinematic equations, write a formula that gives vf in terms of t, xi, xf, and a. 2. Relevant equations 3. The attempt at a solution I tried using vf = vi + at but it was incorrect. Is there another way where i can solve for vf using the 4 needed variable above? thanks Also I have tried using this : (xf-xi)+(1/2at) = vi then substitute vi with this equation vf = vi+at. After that I got (xf-xi)+at = vf but it was still incorrect.