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Homework Help: Fluid / Air Pressure/ Roof

  1. Apr 9, 2008 #1
    1. The problem statement, all variables and given/known data

    The roof of a house has an area of 92.8 m^2. In a violent storm the air blows across the roof at a speed of 106.8 km/hr.

    2. Relevant equations

    Assuming that the air has a density of 1.25 kg/m^3, what pressure difference is created by the storm between the air outside and inside the house?

    3. The attempt at a solution

    Pressure/s = Area * density / speed (m/s)
    = 92.8 * 1.25 / (106.8/3.6)
    = 3.91 atm*s

    how do i find the time?
    or am i doing the whole thing wrong?
     
  2. jcsd
  3. Apr 9, 2008 #2
    Maybe this has something to do with the Bernoulli's principle:

    [tex]\frac{\rho v^{2}}{2}+\rho g h + p = const.[/tex]

    But then you don't need the surface...
     
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