A gravity retaining wall is shown in Fig. $1.$ Calculate the factor of safety with respect to overturning and sliding using the Rankine active earth pressure, given the following data:

Wall dimensions: $H=6m,x_1=0\mathrm{.}6m,x_2=2m,x_3=2m,x_4=0\mathrm{.}5m,x_5=0\mathrm{.}75m,x_6=0\mathrm{.}8m,D=1\mathrm{.}5m$

Soil properties: ${}_1=16\mathrm{.}5k\frac{N}{m^3},{}_1^{\text{'}}={32}^0,{}_2=18k\frac{N}{m^3},{}_2^{\text{'}}={22}^0,c_2^{\text{'}}=40k\frac{N}{m^2}$

Use ${}_{\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{t}\text{e}}=23\mathrm{.}58k\frac{N}{m^3}.$ Also use ${}^{\text{'}}2=\frac{2}{3}{}^{\text{'}}2$ and $c{a}^{\text{'}}=\frac{2}{3}{c}^{\text{'}}2,$ and $P_p=0.$