All the energy was directed "backward" from the point of view of the bored crew members who were presumably monitoring all of this in the station at the "handle" end of the whip. They were moving a lot faster than the flivver. In order to make physical contact with the approaching craft, they had to reach "back." And "reach" wasn’t really the right term; they had to punch backward with explosive suddenness to match the flivver’s much lower velocity. This was the kind of task that bullwhips were made for.