Superman (a character by DC comics) leaps a tall building in a single bound, without the use of flight

Superman (a character by DC comics) leaps a tall building in a single bound, without the use of flight. The building, Lexcorp tower, is equal in height to Sears Tower (1706. feet). He travels in a completed arc and lands on the opposite side of the building. There are 3.28 feet in 1 meter. Ignore any horizontal motion and only examine the vertical motion of Superman. Assume he jumped the minimum height required to clear the building.
a) what was Superman's vertical speed as soon as he left the ground?