You're driving parallel to train tracks at 40.0 km/h when a train passes you, going a steady 105 km/h. A track crossing is up ahead, so you begin to speed up at 6.50 m/s2. How far do you drive before you pass the train?

Answer 1

You want the distances to be the same after t hours. So, noting that

6.5 m/s^2 = 23400 km/hr^2

105t = 40t + 23400/2 t^2
t = 1/180 hr

So, you overtake the train after 0.583 km

I hope you were not uncomfortable with the unusual units; you can always convert the speeds to m/s if you want. :-)