In an experiment performed at the bottom of a very deep vertical mine shaft, a ball is tossed vertically into the air with a known initial velocity of 10.0 m/s, and the maximum height the ball reaches (measured from its launch point) is determined to be 5.121 m. Knowing the radius of the earth, 6370 km,and the gravitational acceleration at the surface of the earth,9.81 m/s^2, calculate the depth of the shaft.