A light train made up of two cars is traveling at 100 km/h when the brakes are applied to both cars. Knowing that car A has a mass of 35 Mg and car B a mass of 20 Mg, and that the braking force is 35 kN on each car, determine (a) the distance traveled by the train before it comes to a stop, (b) the force in the coupling between the cars while the train is showing down.