A 62.7-kg person jumps from rest off a 2.98-m-high tower straight down into the water. Neglect air resistance. She comes to rest 1.09 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This force is nonconservative.

please help :D? i really don't get this question

Calculate speed when body hits water:

(1/2) m v^2 = m g h
so
v = sqrt(2 g h)

average force = change in momentum /time to stop

change in momentum = m(v-0)

time to stop = distance/average speed = 1.09 / (.5 v)