$4\mathrm{.}5-2$ A simple beam $AB$ is subjected to a counterclockwise couple of moment $M_0$ acting at distance a from the left$-$hand support $($see figure$).$ Draw the shearforce and bending$-$moment diagrams for this beam.

Also draw the shear$-$force and bending$-$moment diagrams if a second moment $M_0$ is added at distance a from support $B.$

PROBLEM $4\mathrm{.}5-2$