1. The problem statement, all variables and given/known data If a car is going 30m/s and see's an accident 60 meters in front of him/her, at what deceleration must the car apply brakes in order to stop in time? 2. Relevant equations s(t) = [tex]\int(v)t[/tex] v(t) = [tex]\int(a)t[/tex] 3. The attempt at a solution So I know the physics equation that I could use for this very easily (vf^2 = vo^2+2a \Delta (x) But, for my calculus class I have to do it obvously with only calculus. I don't know why i can't get this, but I have a feeling it will be on my exam tomorrow so I need to know how to show the work. I am setting it up that V(t) = at + Vot, then integrating to find s(t), but after this point, I have s(t) = 1/2 a t^2 + vot +s(0) s(0) is 0 for this case because it is from the point of applying brakes.... Anyway, where do I go from here? I am kinda lost and really don't know why. Any help greatly appreciated, thanks!