A flat roof is very susceptible to wind damage during a thunderstorm and/or tornado. If a flat roof has an area of 500 m2 and winds of speed 39.0 m/s blow across it, determine the magnitude of the force exerted on the roof. The density of air is 1.29 kg/m3.

The magnitude of the force exerted on the roof is 490522.5 N.

Explanation:

The given data is as follows.

Below the roof, = 0 m/s

At top of the roof, = 39 m/s

We assume that is the pressure at lower surface of the roof and be the pressure at upper surface of the roof.

Now, according to Bernoulli's theorem,

             =

             =

             = 981.045 Pa

Formula for net upward force of air exerted on the roof is as follows.

          F =

             =

             = 490522.5 N

Therefore, we can conclude that the magnitude of the force exerted on the roof is 490522.5 N.