A subway train, departing from the station, can reach a speed of 72 km / h in 20 seconds.

A subway train, departing from the station, can reach a speed of 72 km / h in 20 seconds. Determine the acceleration of its movement. What is the route the train travels?

Given:

v = 72 kilometers per hour = 20 meters per second – the speed that the train develops during the time interval t;

t = 20 seconds – time span.

It is required to determine the train acceleration a (m / s2) and its traversed path S (meter) in time t.

According to the condition of the problem, the train starts moving, departing from the station, that is, without an initial speed. Then:

a = v / t = 20/20 = 1 m / s2.

S = a * t ^ 2/2 = 1 * 20 ^ 2/2 = 1 * 400/2 = 400/2 = 200 meters.

Answer: the acceleration of the train is 1 meter per second squared, in 20 seconds the train travels a distance equal to 200 meters.