$12\mathrm{.}2$ Use Eq$.(12\mathrm{.}3),$ Figure P$12\mathrm{.}2,$ and the following values to determine the at$-$rest lat$-$

eral earth force per unit length of the wall. Also find the location of the resultant.

$H=5m,H_1=2m,H_2=3m,=15\mathrm{.}5k\frac{N}{m^3},{}_{\text{s}\text{a}\text{t}}=18\mathrm{.}5k\frac{N}{m^3},{}^{\text{'}}=34,$

$c^{\text{'}}=0,q=20k\frac{N}{m^2},$ and OCR $=1.$