A jumper of mass m=55 kg starts in a crouched position with the jumper's center of mass at a position y1=0 m. Just before the jumper leaves the floor, his or her center of mass is at y2=0.7 m. From another measurement, you have found that the velocity of the jumper's center of mass has only a y component of v2=2.8 m/s as the jumper's feet leave the floor.
assume Ffloor changes while the jumper goes from the crouched to the lift-off position. While the jumper's feet are in contact with the floor assume the force decreases linearly or
Ffloor(y) = -C[y-(y2-y1)],
where y is the changing position of the center of mass, and C is a positive constant. Note that when y=y2-y1 this force goes to zero and, of course, once the jumper's feet leave the floor this force of the floor on the jumper must be zero.
For the initial conditions above, find the maximum value of Ffloor and so the required strength of the floor.