The plan view of the building shown below has four concrete shear walls and an AC unit. The west wall has a parapet of 4 feet above the roof. The unit weight of the roof and walls are 50 and 62 pounds per square foot respectively. The AC unit weighs 2.0 tons. The relative rigidities of all walls are shown and all walls have the same thickness of 4.0 inches. Seismic design category (SDC) C and Sos=0.80g. Consider the unit weight of concrete 150 pcf. R 8 AC unit R=8 60 R=7 12 AC unit PLAN 1- Calculate the coordinates (x, y) of the center of mass (CM) 2- Calculate the relative rigidity (R) of all walls 3- Calculate the coordinates (x, y) of the center of rigidity (CR) using the given rigidities. SECTION G-C