4-56. The rigid bar supports the 4-kN load. Determine the normal stress in each A-36 steel cable if each cable has across-sectional area of 25 mm^2. 4-57. The rigid bar

is originally horizontal and is supported by two A-36 steel cables each having a cross-sectional area of 25 mm^2. Determine the rotation of the bar when the 4-kN load is applied.