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Homework Help: Total force by molasses on inside of tank

  1. Apr 13, 2008 #1
    1. The problem statement, all variables and given/known data
    On January 15, 1919, a cylindrical tank of molasses ruptured, and poured out over the streets of Boston in a 9 m deep stream. Pedestrians and horses were killed, and buildings were knocked down.

    Suppose the tank was 87.7 m high and 3.37 m diameter, and it was full of molasses (density 1630 kg/m3). Find the total force exerted by the molasses on the inside of the tank before it broke.



    2. Relevant equations
    P=F/A
    P=ρgh
    pressure of air 1.103x10^5 use Greek letter ϕ
    A is the area
    ρ is density
    d is diameter

    3. The attempt at a solution

    since the pressure changes, i think i should integrate to find force.

    ΔF=P∙ΔA=∫(ϕ+ρgh)πd∙Δh

    after integrate i get : F=ϕπdH+(ρgπdH^2)/2

    it's right?
     
  2. jcsd
  3. Apr 13, 2008 #2
    by the way, i am sure if we need to consider the air pressure or not.
     
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