The calculation is straight forward. The coefficient given for rolling resistance is 0.0004 for rail which means that .0004W is the frictional resistance of th

The calculation is straight forward. The coefficient given for rolling resistance is 0.0004 for rail which means that .0004W is the frictional resistance of the track. Given a train going at velocity v then the train is accelerated by friction at a rate of -.0004W/m (F=ma so a=F/m) which is equal to -.0004g (W=mg). Then to stop it will take t = v/.0004g which means that you will travel vt/2 in that time. For example, if a train is cruising along at 30 mph (44 fps) then it takes 44 ft/s / .0004(32.2 ft/s^2) = 3416 seconds to stop which means that the train travels 14.2 miles under ideal conditions.