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Homework Help: Variation of Pressure with Depth

  1. Nov 30, 2011 #1
    1. The problem statement, all variables and given/known data
    By what factor is the total pressure greater at a depth of 850 m of sea water than at the surface where the pressure is one atmosphere? (water density = 1000 kg/m3, one atmosphere pressure = 1.01 x 105 Pascals (N/m2), g = 9.8 m/s2 )


    2. Relevant equations
    P=P(initial)+ρgh


    3. The attempt at a solution
    P=(1.01x10^5)+(1000kg/m^3*9.8m/s^2*850m)
     
  2. jcsd
  3. Nov 30, 2011 #2
    Your calculation gives you the pressure at the depth of 850m. The question is worded....'by what factor is the total pressure greater at a depth of 850m..... I think this means you are expected to give your answer as a ratio??
     
  4. Nov 30, 2011 #3
    ok, well how would I do that? the possible answers to the question are a. 100, b. 83, c. 74, d. 19. That is where I am stuck.
     
  5. Nov 30, 2011 #4
    using P = hρg I got the pressure due to the water to be 8.33 x 10^6 Pa
    Atmospheric pressure is 1.01 x 10^5 Pa
    Get the ratio ????
     
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