Two students are on a balcony 20.2 m above the street. One student throws a ball vertically downward at 13.3 m/s; at the same
instant, the other student throws a ball vertically upward at the same speed. The second ball just misses the balcony on the way down. How far apart are the balls 0.406 s after they are thrown? The acceleration of gravity is 9.8 m/s2.