Latter-day infidels have succeeded in constructing a modern Tower of Babel with a height equal to three times the radius of the Earth. To celebrate the accomplishment, the barbarians are celebrating with a sacrifice to appease the gravitational gods. The peter-principled Dean of Deans (Maximus incompetus) is dropped from the tower with zero initial speed and plummets toward the Earth. Neglect all histrionics and atmospheric effects. Determine the speed at impact with the surface of the Earth in km/s.