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Homework Help: How can you determine the net force of a bottle

  1. Aug 30, 2004 #1
    How can you determine the net force of a bottle who's contents are kept under 2 atm of pressure, and it has a 1 cm opening for example?

    a1v1=a2v2 doesn't seem to apply, and the flowrate=dav doesn't seem to either. I suspect it is bernoulli's equation, but I am unsure.

    I know P=F/A, but how do you find the pressure? is it simply the pressure difference?
  2. jcsd
  3. Aug 30, 2004 #2
    Also, if the bottle has two openings facing in the same direction, how does that work? Do you add the area of the two holes and use that for area, or is it two seperate cases?
  4. Aug 30, 2004 #3


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    Pressure is defined as "force divided by area" or P= F/A so F= P*A. You are given that the pressure is 2 atmospheres and the fluid is coming out an area of pi cm2 (I am assuming that the "1 cm" hole has radius 1 cm. If it is diameter= 1 cm, then the area is pi/4 cm2).

    Yes, if you have two holes of area A1 and A2, then that is the same as 1 hole of area A1+ A2.
  5. Aug 31, 2004 #4
    Does the outside pressure matter?
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