In the beam shown in the adjacent figure, the external forces are the applied force at point A ( − F e y {\displaystyle -F\mathbf {e} _{y}} ) and the reactions at the two support points O and B ( R O = R O e y {\displaystyle \mathbf {R} _{O}=R_{O}\mathbf {e} _{y}} and R B = R B e y {\displaystyle \mathbf {R} _{B}=R_{B}\mathbf {e} _{y}} ). The reactions can be computed using balances of forces and moments about point A, i.e.,