Because the speed reaches 6 meters per meter after 5 seconds, we can know A = 1.2m/s 2 according to at = v.
After 10s, it goes from 6m/s to 0, so at=v, and a = 0.6m/s 2 is obtained (A only considers the size, not the direction).
It is found that the advancing distance of the acceleration process is1/2×1.2× 52 =15m,
Distance of uniform motion: 6× 10=60m.
Distance of acceleration process: 6×10-1/2× 0.6×102 = 30m.
Therefore, the mine depth is 15+60+30= 105m.