1. The problem statement, all variables and given/known data Sam is running at 3.8 m/s and is 75m behind John who is running at a constant velocity of 4.2m/s. If Sam accelerates at 0.15m/s^2, how long will it take him to catch John? 2. Relevant equations d = (vf+vi/2)t vf = vi + at d = vit + 1/2at^2 vf^2 = vi^2 + 2ad d = vft - 1/2at^2 3. The attempt at a solution I have asked this before, but have now come back with a little more understanding than before. I've done the following so far: Xs (displacement of Sam) = viΔt + 1/2aΔt^2 = (3.8m/s)Δt + (0.075m/s^2)Δt^2 Xj (displacement of John) = 75 + 4.2m/sΔt [-> from: (xf-xi) = VavΔt xf = xi + VavΔt ] --- ... Ok so now I do (3.8m/s)Δt + (0.075m/s^2)Δt^2 = 75 + 4.2m/sΔt to find the time when they are in the same position/displacement, correct? But I'm so confused as to what I would do after that? EDIT; Also, I got 1005.33s for the time, and I don't think that's right?