Problem $6.$ Consider the bone$-$prosthesis structure under torsion. In class,

we used the compatibility equation $($the equality of the twists, ${}_P={}_b)$ to

obtain a relation between $T_b$ and $T_p.$

$($a$)$ Write down this relation.

$($b$)$ What are the bone and prosthesis shear stresses $({}_z^b$ and ${}_z^p)$ at their

interface