Answer:
2.2 W where W is the weight of the jumper.
Explanation:
A) use the formula
V^2 = 2gh= 2*9.81*60
that gives
V = 3.43 m/s
b) W = mg
during the jump , the displacement of the body is d =0.5m
so the acceleration a = (V^2-Vo^2)/2d = 11.76 m/s^2
net force applied by ground = m(g+a) = W/g(g+a)
= 2.2 W