A possible circular failure surface has a radius of 22m and is passing through the toe of the cut slope and through a point 5 m away on the top ground from the edge of the cut. The weight of the failure mass is 1500kN and its centre of gravity is at a distance 10 m from the centre of the failure circle. The properties of soil are C=40kN/m$^{2}$, $\psi=18^{\circ}$ and $\gamma=20 kN/m^{3}$. Determine factor of safety that would be available on the said failure surface for the cut. Use friction circle method.