Problem $4\mathrm{.}4$ An isolated T$-$beam is composed of a flange $700$ mm wide and $100$ mm in thickness which is cast monolithically with a web $250$ mm wide. The depth of the web is $650$ mm below the bottom surface of the flange with a total depth of the section of $750$ mm$.$ Tensile reinforcement consists of $632$ mm diameter bars placed in two layers. The cover to the centroid of the bar group from the bottom of the beam is $100$ mm$.$ Assume that the concrete fc$=21$ MPa and that the steel has fy$=420$ MPa. Determine the nominal moment capacity of the beam.