Determine the nominal uniform load Wn (including beam weight) that will cause a bending moment equal to Mn. fc’= 3000 psi and fy= 60,000 psi. 
a=(4*1.27*60,000)/(0.85*3000*16) now we can calculate nominal moment after acquiring ‘a’ Mn=5.08*60,000*(23-7.47/2) Mn=5871972lb-in=489.33K-ft the maximum moment for a simply supported beam=(w*L^2)/8 
