A person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of vi = 11 m/s. The cliff is h = 47 m above the water's surface, as shown below.

Answer 1

You gave the details but failed to ask the question.

If you want to know how far away from the (vertical) cliff the stone hits the water, multiply 11 m/s by the time T that it takes the stone to fall to the water's surface.

(g/2)T^2 = 47 m
T = sqrt (2*47/9.8)= 3.1 s