We know that this is a constant acceleration problem, so we can look at the equations that describe motion with constant acceleration to find a way to calculate the answer. What was the acceleration of the car? 20m=1/2akl? V V = V + at 0 X - X X - V X o x - x 0 = = = 1 2 + 2 a (x - xo 1 vot + 2 vt 1 at ( v + v) t N| 2 at 2