A watertight bulkhead 22 ft high forms a temporary dam for some construction work. The top 12 ft behind the bulkhead consists of sea water with a density of 2 slugs/ft³, but the bottom 10 ft begin a mixture of mud and water can be considered a fluid of density 4 slugs/ft³. Calculate the total horizontal load per unit width and the location of the center of pressure measured from the bottom.