Every few years, winds in Boulder, Colorado, attain sustained speeds of 45.0 m/s

Question

Every few years, winds in Boulder, Colorado, attain sustained speeds of 45.0 m/s (about 100 miles per hour) when the jet stream descends during early spring. Approximately what is the force due to the Bernoulli effect on a roof having an area of 210 m2? Typical air density in Boulder is 1.14 kg/m3, and the corresponding atmospheric pressure is 8.89 104N/m2. (Bernoulli's principle as stated in the text assumes laminar flow. Using the principle here produces only an approximate result, because there is significant turbulence.)
______________ N

Explanation / Answer

Bernoullis theorem :-
=>P1 + h1dg + 1/2dv11 = P2 + h2dg + 1/2dv22
=> P1- P2 = 1/2dv2 {as h1 = h2}
=>P = 1/2 x 1.14 x (45)2
=>P = 1154.25 Pa
By P = F/A
=>F = PA = 1154.25 x 210 = 242392.5 N

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