The section modulus of a rectangular light beam 25 metres long is 12.500 cm3. The beam is simply supported at its ends and carries a longitudinal axial tensile load of 10 tonnes in addition to a point load of 4 tonnes at the centre. The maximum stress in the bottom most fibre at the mid span section, is

• 13.33 kg/cm2 tensile
• 13.33 kg/cm2 compressive
• 26.67 kg/cm2 tensile
• 26.67 kg/cm2 compressive
• none of these.