a person is jumping...

Question

zephyr141 · Answer

An average person can reach a maximum height of about 60 cm when jumping straight up from a crouched position. During the jump itself, the person's body from the knees up typically rises a distance of around 50 cm. To keep the calculations simple and yet get a reasonable result, assume that the entire body rises this much during the jump.

1) With what initial speed does the person leave the ground to reach the height of 60 cm?

2) In terms of this jumper's weight W, what force does the ground exert on him/her during the jump?

zephyr141 · Answer

so for the first one i just used the kinematic equation$$v^2=v_0^2+2ah$$and got 3.43 m/s for v(initial) now for the second part...