Consider a frictionless retaining wall $($the interface between the soil and wall has friction angle of zero$)$

with a height of $8$ m$.$ The unsaturated soil behind the wall is sand with drained friction angle of $27$ degrees and unit

weight of $18\mathrm{.}7$ kN$/$m$^3.$

A$)$ Plot the variation of Rankine active pressure with depth.

B$)$ Find the magnitude and location of action of the Rankine active force.