A runner runs and jumps off a cliff into the water below. If the runner takes up running a 9.37 m/s and lands in the water 2.0 m away from the cliff's edge: How tall is the cliff?

Answer 1

The time it takes to hit the water is
t = 2.0/9.37 = 0.213 s

Now calculate how far he falls in that time.

Y = (g/2) t^2

That will be the cliff height.