The dam is constructed over a pervious foundation causing an uplift hydrostatic pressure that varies linearly from a maximum hydrostatic pressure at the heel to zero at the location of the drain. use specific weight of water equals to 9.81 kn/m3 . calculate the following: 1) location of the resultant reaction at the base (7 points) 2) factor of safety against sliding if coefficient of friction is equal to 0.75 (4 points) 3) factor of safety against overturning (4 points