Hi, I'm trying to find out the time it takes to travel a known distance, but with a capped speed. For example, let's say a train has an acceleration rate of 0.8m/s/s, and a top speed of 72km/h, ie: 20m/s. It's going to make a 12km journey, accelerating to it's top speed from rest. How long does it take? I have the formula: d=vt + 1/2at2 where v = initial velocity, in this case 0. d = distance, a = acceleration. I'm having trouble making "t" the subject. Because the train is starting from rest, with an initial velocity of 0, I'm ignoring that part of the equation entirely. I came up with this: t = (√2d)/a Is that correct? Thanks in advance. Nige'