Given that:

W = 637N, h = 19.6m, S = 2m, g = 9.8m/sec^{2 }

Let, F_{r} = Average resistance

Initial velocity of man u = 0,

V^{2} = u^{2} + 2gh

= 0 + 2 X 9.8 X 19.6

V = 19.6 m/sec ...(i)

Now distance traveled in water = 2m,v = 0, u = 19.6m/sec now apply

V^{2} = u^{2} – 2as

0 = 19.62 – 2a X 2

a = 96.04m/sec^{2 }...(ii)

Since, net force acting on the man in the upward direction = F_{r} – W But the net force acting on the man must be equal to the product of mass and retardation.

F_{r} – W = ma

F_{r} – 637 = (637/g) X 96.04

**F**_{r} = 6879.6N.