The tibia bone in the lower leg of an adult human will break if the compressive force on it exceeds about 4 x 10^5 n (we assume that the ankle is pushing up). suppose that you step off a chair that is 0.40 m above the floor. if landing stiff-legged on the surface below, what minimum stopping distance do you need to avoid breaking your tibias? indicate any assumptions you made in your answer to this question.