A simply supported beam of span 'l' is loaded (as shown in the given figure) with a uniformly varying load of intensity w_{1}/unit length at 'A' to w_{2}/unit length at 'B'. A The shear force at the support 'B' is given by

The effort 'P' to be applied horizontally to pull a weight 'W' on a plane inclined at an angle α with the horizontal is given by (tan θ is the coefficient of friction)

If two triangulation signals of 6.75 m height each, are to be just visible over ground mutually, what is the maximum distance between their locations on the ground surface ?