A wind with speed 45ms blows across a roof 20 m long and 12

A wind with speed 45m/s blows across a roof 20 m long and 12 m wide. The pressure inside the room is 1 atm. What is the net force on this roof due to the pressure difference inside and outside the roof? (The density of air is equal to 1.3 kg/m^3)

Solution

net force on the roof is

            P = F / A

            F = P A  

               = ( 1.01x10⁵ pa ) ( 20 m ) ( 12 m )

              = 242.4 x10⁵N