Well, I think this one is pretty simple, but still, I don't know how to solve it. We all know that for uniform velocity in a straight line the following equation sets the relationship between time and distance traveled: S = So + Vt (Eq. 1) When it comes to uniformly accelerated motion, the only difference is that the velocity is changing constantly, according to the following equation: V = Vo + at (Eq. 2) Now, if you insert Eq. 2 in Eq. 1 you get: S = So + Vot + at^2 (Eq. 3) But we all know the correct equation is S = So + Vot + at^2/2! Besides, the second derivative of Eq. 3 is 2a, when the correct one is, by definition, a, obviously. So it's clearly wrong. What's the deal with this?