While standing at the edge of the roof of a building, a man throws a stone upward with an initial speed of 7.59 m/s. The stone subsequently falls to the ground, which is 18.9 m below the point where the stone leaves his hand. At what speed does the stone impact the ground? Ignore air resistance and use =9.81 m/s2 for the acceleration due to gravity. I need help finding out the impact speed, please.