A simply supported prestressed concrete beam of 300 × 500 mm in c/s is subjected to a superimposed load of 20 kN/m over a span of 10 m. If a prestressing force of 1000 kN is applied through a straight tendon located along the centroidal axis then what is the extreme top fiber stress at the end support:
1
20 mPa
2
6.67 mPa
3
19.33 mPa
4
26.67 mPa