From the train moving at a speed of v = 72 km / h, the last carriage is uncoupled, which stops after a time t = 10 s

From the train moving at a speed of v = 72 km / h, the last carriage is uncoupled, which stops after a time t = 10 s. Determine the distance s between the train and the car at this moment. The movement of the carriage shall be considered uniformly slowed down.

Data: V (constant train speed) = 72 km / h (20 m / s) = V0 (initial speed of the last carriage); t (duration of braking of the last car) = 10 s; the movement of the last carriage is slowed down.

The distance between the train and the last carriage is determined by the formula: S = S1 – S2 = V * t – (V0 * t – 0.5 * a * t ^ 2) = V * t – V0 * t + 0.5 * (V0 / t) * t ^ 2 = 0.5 * V0 * t.

Calculation: S = 0.5 * 20 * 10 = 100 m.

Answer: After 10 seconds, the distance between the train and the last carriage will be 100 meters.