The planar structure RST shown in the figure is roller-supported at $\mathrm{S}$ and pin-supported at R. Members RS and ST have uniform flexural rigidity (EI) and $S$ is a rigid joint. Consider only bending deformation and neglect effects of self-weight and axial stiffening.
When the structure is subjected to a concentrated horizontal load $P$ at the end $\mathrm{T}$, the magnitude of rotation at the support $\mathrm{R},$ is
(A) $\frac{P L^{3}}{12 E I}$
(B) $\frac{P L^{2}}{12 E I}$
(C) $\frac{P L^{2}}{6 E I}$
(D) $\frac{P L}{6 E I}$
The planar structure RST shown in the figure is roller-supported at $\mathrm{S}$ and pin-supported at R. Members RS and ST have uniform flexural rigidity (EI) and $S$ is a rigid joint. Consider only bending deformation and neglect effects of self-weight and axial stiffening.
When the structure is subjected to a concentrated horizontal load $P$ at the end $\mathrm{T}$, the magnitude of rotation at the support $\mathrm{R},$ is
(A) $\frac{P L^{3}}{12 E I}$
(B) $\frac{P L^{2}}{12 E I}$
(C) $\frac{P L^{2}}{6 E I}$
(D) $\frac{P L}{6 E I}$