The maximum energy a bone can absorb without breaking is surprisingly small. For a healthy human of mass \(60 \mathrm{~kg}\), experimental data show that the leg bones of both legs can absorb about \(200 \mathrm{~J}\).

a. From what maximum height could a person jump and land rigidly upright on both feet without breaking his legs? Assume that all the energy is absorbed in the leg bones in a rigid landing.

b. People jump from much greater heights than this; explain how this is possible.