Determine the position of maximum bending moment when two loads, $12$ kN and

$4$ kN $,$ at a fixed distance of $4\mathrm{.}5$ m apart, crosses a girder of $25$ m span. Calculate

the magnitude of the maximum bending moment and also the position of the

point at which the bending moment is same in the two cases:

$($a$)$ when the $12$ kN load is over the point

$($b$)$ when the $4$ kN load is over the point;

The ends of the girder may be considered to be simply supported.