posted by Anon
A swimmer launches himself upwards from a springboard 5.0 m above
the surface of the water in a swimming pool. His trajectory is (almost) vertical, and from the top of his trajectory he passes the springboard in just half of the time he takes to reach the water. How high above the springboard does he rise?
let h = height above board
h = (1/2) g (t/2)^2
h + 5 = (1/2) g t^2