text: in physics, is the distance formula d = vit + 1/2at^2 or d = vit + at^2? where vi = initial velocity a = acceleration t = time the first one.  you can also double check, as all four equations of motions are interlinked. e.g. sub v=u+at into s = 1/2 (u+v)t you will get s = ut + 1/2at^2. **note: u = vi, while s = d. others remain the same.  hope this helps=)