$7\mathrm{.}1$ and $7\mathrm{.}2$ Determine the internal forces $($axial force, shearing force, and bending moment$)$ at point $J$ of the structure indicated. $7\mathrm{.}1$ Frame and loading of Prob. $6\mathrm{.}78.$

Fig. P$6\mathrm{.}78$