The hollow precast beam has a simple span of 10 m and carries a dead load of 2350 N/m (including its weight) and a live load of 5490 N/m. Determine the stress diagram for the beam if it is subjected to a prestressing force of 353 KN applied 40 mm from the bottom of the beam. The Inner dimensions of a 400 mm x 400 mm are 240 mm x 240 mm