A tuning fork with a name plate frequency of 512 hz falls from an over pass as it is struck onto the railing. Two Physics Nerds are below the overpass, and the difference of their elevations is 12.60m. They each hear a frequency greater than 512 hz as the fork moves toward them; the difference in the frequencies they hear is 6.84 hz. Determine their respective distances below the overpass. The speed of sound is 342 m/s.