What is the fractional decrease in pressure when a...

Answers ( 4 )

  1. juho nevala
    juho nevala
    we know that,

    change in pressure , ?P = ?gh

    where,
    ? = density of medium = 1.184 kg/m3 (for airat 250 C)
    g = acc due to gravity = 9.8 m/s2
    h = height change = 35 m

    => ?P = 1.184*9.8*35 = 406.112Pa

    1 atm = 101325 Pa
    => 1 Pa = 1/101325 atm
    => 406.112 Pa = 406.112/101325 = 0.004atm   (approx)
  2. eddie andrews
    eddie andrews
    The variation of Pressure with allitude is given by theequation
                                    P = Poe - ( ?og /Po)h
    The constant ( ?og / Po) = (1.29kg/m3*9.8m/s2) / ( 1.013*105N/ m2)
                                         = 1.25*10-4 / m
    Therefore,               P = 1.004*105 N/m2
    The fractional decrease P -Po = 442N/m2
  3. viktor sauer
    viktor sauer
    We know that the pressure is the weight ofthe column of height h of air (having density ?) per unitof area or P=W/A
    W= mg ( assuming these 35 m are close tothe Earths surface)
    m = ?V
    V= h A
    Puting it together we have
    P=W/A= mg/A = ?Vg/A= g? h A/ A
    P= g?h
    or the change in pressure?P=P=g?h
    ?P= 9.81 x ? x 35 =343?
    the density of air at see level can varybased on themperature from 1.4 - 1.15 kg/m3 (temperaturerange from -25 to +35 deg C) http://en.wikipedia.org/wiki/Density .
  4. giulia rodrigues
    giulia rodrigues
    The fractional decrease in pressure = ?gh =1.15kg/m3*9.8*35 = 389.4*10-5 Pa

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