[填空题]
From what maximum height cpbpr cgk4*f 06an a 75-kg person jump without breaking the lower lesagakq0gy 8..l.n e, gg bone of either leg? Ignore air resi 0a ggy..a., gks8qlnestance 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
