A 56 kg swimmer jumps off of 15 m tower. Find the swimmers velocity when hitting the water.
well, If he jumped up, all bets are off. If he just fell off then:
v = sqrt (2 g h)
because
m g h = (1/2) m v^2 conservation of energy
g h = (1/2) v^2
so
v = sqrt (2*9.81*15) = 17.2 meters/second