[填空题]
From what maximum height can a 75-kg person jump without breaking the lf.uw(fzv7i 4*(sl xncyp89tb+k-.tc 7 s nwnlower leg bnl8ny t.9s7tbkw+ cp-one of either leg? Ignore air resistance and assume the 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
