Hi Guys, its my first post here and I have a feeling that I'll be using this forum as a resource. Maybe once I learn enough I'll be able to contribute in solving other peoples' hw problems. Anyway, to the problem: 1. The problem statement, all variables and given/known data A commuter train travels between two downtown stations. Because the stations are only 1.42 km apart, the train never reaches its maximum possible cruising speed. During rush hour the engineer minimizes the travel interval deltaT between the two stations by accelerating for a time interval deltaT1 at a1 = .100m/s^2 and then immediately braking with acceleration a2 = -.390 m/s^2 for a time interval deltaT2. Find the minimum time interval of travel deltaT and the time interval deltaT1. So we are given: A1 = .1 m/s^2 A2 = -.390 m/s^2 V i1 = 0 m/s Vf2=0m/s delta X = 1420 m 2. Relevant equations kinematics equations 3. The attempt at a solution I feel like I'm overthinking this one and am overlooking a relatively simple solution. I know can't use 1420 as deltaX because the train does not accelerate at one rate for the entire distance. Now I only have 2 variables for the first half of the problem. Please any hints will greatly help asap. Thanks!