$$\begin{gathered} =\frac{(55,120 \mathrm{N})(700 \mathrm{mm})}{(320 {\mathrm{mm}}^2)(105,000 \mathrm{N}/{\mathrm{mm}}^2)} \\ =1.1483 \mathrm{mm} \end{gathered}$$

Backsubstitute to calculate the deflection of the rigid bar at $\mathrm{D}$:

$$\begin{gathered} {\mathrm{v}}_{\mathrm{D}}=2{\mathrm{v}}_{\mathrm{C}}=2(1.1483 \mathrm{mm}) \\ =\mathbf{2}\mathbf{.}\mathbf{30}\mathbf{ }\mathbf{mm} \left(\mathrm{downward}\right) \end{gathered}$$