Problem 10.64 the maximum energy a bone can absorb without breaking is surprisingly small. for a healthy human of mass 67 kg , experimental data show that the leg bones can absorb about 200 j . part 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. neglect any friction.

h = 0.30 m

Explanation:

A person jumping from height h would possess potential energy = m g h

which will convert completely into kinetic energy as person hits the ground. Now, the maximum energy absorbed by the person can be = 200 J

m = 67 kg

g = 9.8 m/s²

⇒ m g h = 200 J

⇒ h = 200 J / (67 kg × 9.8 m/s²) = 0.30 m

Hence, a person can land safely on both legs without breaking them from a height of 0.30 m only.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.