. How quickly or, in other words, with what velocity
does the man advance relative to the embankment during the process? The only possible answer seems to result from the following consideration: If the man were to stand still for a second, he would advance relative to the embankment through a distance
equal numerically to the velocity of the carriage. As a consequence of his walking, however, he traverses an additional distance
relative to the carriage, and hence also relative to the embankment, in this second, the distance
being numerically equal to the velocity with which he is walking. Thus in total he covers the distance
