physics
posted by Katie .
A diver running 2.4 m/s dives out horizontally from the edge of a vertical cliff and 2.6 s later reaches the water below. How high was the cliff?

The horizontal distance does not change the time it takes to fall through the height of the cliff. It's there probably to throw you off, or there's a second part of the question.
What is important is the initial velocity is horizontal, so the vertical component, u, is zero.
vertical drop
S = ut+(1/2)gt²
= 0 + (1/2)(9.8)*2.6²
=? 
0.72