The roof plan and elevation view for a rectangular building are shown in Figure $2$ below. The nominal wind load acting on the building can be idealized by a uniform pressure of $25$ psf acting on the southern wall.

a$)$ Determine the uniform wind load W $($plf$)$ transmitted to the roof diaphragm from the wall panels.

b$)$ If the east & west walls each have a shear wall that is $18\text{'}$ high and $10\text{'}$ wide, determine the design overturning moment of the shear walls.