A 52.2 kg parachutist lands moving straight downward with a speed of 3.75 m/s. If the parachutist comes to rest with constant acceleration over a distance of 0.794 m, what force does the ground exert on her?

Answer 1

average speed during crash = 3.75/2
so
time to stop = .794 / (3.75/2)

acceleration = change in speed / change in time
or
a = (0 - -3.75) / [.794 / (3.75/2) ]
and
F = m a = 52.2 a