A propped cantilever of span $$L$$ carries a vertical concentrated load at the mid-span. If the plastic moment capacity of the section is $${M_P}$$, the magnitude of the collapse load is

For formation of collapse mechanism in the following figure, the minimum value of $${{P_u}}$$ is $$c{M_P}/L.$$ $${M_P}$$ and $$3{M_P}$$ denote the plastic moment capacities of beam sections as shown in this figure. The value of $$c$$ is ________.

A fixed end beam is subjected to a load, W at $$1/3rd$$ span from the left support as shown in the figure. The collapse load of the beam is

A prismatic beam (as shown below) has plastic moment capacity of $${{M_P}}$$, then the collapse load $$P$$ of the beam is