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Homework Help: Hydrostatic Pressure and Force

  1. Feb 28, 2010 #1
    1. The problem statement, all variables and given/known data

    An aquarium 5ft long, 2 ft wide, and 3 ft deep is full of water. Find the hydrostatic pressure and the hydrostatic force on the bottom of the tank.

    2. Relevant equations

    [tex]P=g*\rho*h[/tex]

    [tex]F=m*g=g*\rho*A*h[/tex]

    [tex]\rho=62.5 \frac{lbs}{ft^3}[/tex]

    [tex]g=32 \frac{ft}{s^2}[/tex]

    3. The attempt at a solution

    [tex]P=(32)(62.5)(3)=6000 \frac{lbs}{s^2}[/tex]

    [tex]F=(32)(62.5)(10)(3) = 60000 \frac{ft*lbs}{s^2}[/tex]

    I know the answers should be [tex]187.5 \frac{lbs}{ft^2}[/tex] and [tex]1875 lbs[/tex], respectively, so I've done these problems wrong. They seem so simple though that I'm thrown for a loop. Are my equations wrong?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Feb 28, 2010 #2
    Nevermind, I realized that since I was dealing with lbs, I was including the force of gravity a second time!
     
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