A tunning fork having a name plate frequency of 512.0Hz falls from an over pass as it is struck onto the railing. Two students are below, and the difference of their elevations is 12.60m. They each hear a frequency greater than the 512.0Hz as the fork moves towards them; the difference in the frequencies they hear is 6.84Hz. Determine their respective distances below the overpass. The speed of sound is 342m/s.