If a man of mass M jumps to the ground from a height ‘h’ and his centre of mass moves a distance ‘x’ after his feet strikes the ground. The average force acting on him is

Final velocity V=2gh If ‘a’ be the retardation of the man, during the period his feet are in contact with the ground, then 0=V2−2ax⇒a=V2/2x=2gh/2x=gh/xN−Mg=Ma=Mghx ∴N=Mg1+hx