Determine the size of the T beam with the specifications shown below with the smallest possible section that can carry the bending moment in the simply supported beam. The maximum allowable stress is 90 kPa.  

 

b) Decide on an alternative I section with the loading condition specified in section (a) if the shearing stress is limited to 3 MPa. Discuss its difference from the previous section in detail. Which section is your preference? Explain your reason.