Question

At a distance L = 400 m from the traffic light, brakes are applied to a locomotive moving at a velocity v = 54 km/h. Determine the position of the locomotive relative to the traffic light 1 min after the application of brakes if its acceleration a = -0.3 m/s².

Answer 1

Since the locomotive moves with a constant deceleration after the application of brakes, it will come to rest in t = v/a = 50 s, during which it will cover a distance s = v²/(2a) = 375 m. Thus, in 1 min after the application of brakes, the locomotive will be at a distance l = L - s = 25 m from the traffic light.