A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is 250 m. Assuming that the pressure inside the house is atmosphere pressure, the force exterted by the wind on the roof and the direction of the force will be (p = 1.2 kg/m) (a) 4.8 x 10' N, upwards (c) 2.4 x 10 N, downwards air (b) 2.4 x 10' N, upwards (d) 4.8 10 N, downwards