A uniform rod AB, of mass 5lb, is hinged at upper end A and hangs down freely. What horizontal force applied at B will be required in order to deflect the rod through 30 degrees from the vertical. Thanks. My attempt: taking moments about A, Fcos30xAB = wxAC = wcos30xAB/2 therefore F = w/2. F= applied horizontal force, w = weight.A 2nd question what does "a gauge of 56.5 ins" mean in rhe context of a railway line?