The $2\mathrm{.}5m3\mathrm{.}5m$ rectangular spread footing placed at a depth of $1\mathrm{.}5$ m supports a vertical load

of $4000$ kN and a moment of $400KN-m,$ as shown in Figure $2.$ Determine the factor of safety,

against bearing capacity failure, using Meyerhof's effective area method.