according to Newton First Law of Motion (Law of Inertia); An object at rest will stay at rest, forever, as long as nothing pushes or pulls on it. An object in motion will stay in motion, traveling in a straight line, forever, until something pushes or pulls on it.
The speed of light generally would be 300000km/s but since the train is moving in the same direction as the light it would apparently appear to be 100000km/s
