[填空题]
From what maximum height cqzy,0mius1 a)pj 59qian a 75-kg person juhz4kaap g+ ,:otc t1v(mp without breaking the lower leg bone of either leg? Ignore air resistance and assume paz gt1 ,ov4c (+aht:kthe CM of the person moves a distance of 0.60 m from the standing to the seated position (that is, in breaking the fall). Assume the breaking strength (force per unit area) of bone is $170\times10^6\mathrm{~N/m^2}$ and its smallest cross-sectional area is $2.5\times10^{-4}m^2$ [Hint: Do not try this experimentally.] m
