(a) What must be the magnitude of the resulting constant deceleration if a collision is to be just avoided?
(b) Assume that the engineer is at x = 0 when, at t = 0, he first spots the locomotive. Sketch x(t) curves for the locomotive and high-speed train for the cases in which a collision is just avoided and is not quite avoided. Do this on paper. Your instructor may ask you to turn in this work.