A golfer hits a shot to an elevated green. The ball leaves the club
with an initial speed of 16 $\mathrm{m} / \mathrm{s}$ at an angle of $58^{\circ}$ above the hori-
zontal. If the speed of the ball just before it lands is $12 \mathrm{m} / \mathrm{s},$ what is
the elevation of the green above the point where the ball is struck?