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Homework Help: Force of sneeze

  1. Nov 23, 2007 #1
    1. The problem statement, all variables and given/known data
    When you stiffle a sneeze, you can damage delicate tissues because the pressure of the air that is not allowed to escape can raise up to 45kpa, if this extra pressure acts on the inner parts of your 0.0084 meter diameter of your eardrum, what is the outward force?

    2. Relevant equations
    work= Pressure * Volume
    Force= work/ circumference

    3. The attempt at a solution

    i have no idea where to start, i know that pressure is related to work by volume but i do not have any measurements for volume, i know i can get volume but i do not know temperature or amount of moles, i know i can said p1v1=p2v2 but i do not know the original pressure or original volume to make that assumption. I just need to know what to look at to start the problem Thanks!!!!
  2. jcsd
  3. Nov 23, 2007 #2
    i also have the formula p=F/Area
  4. Nov 23, 2007 #3
    i think i have solved it by using F= pressure (pie * d/2^2) to get a value of 2.5 N, that kinda seems small but also the area is quite small could anyone tell me if this is a reasonable answer
  5. Nov 23, 2007 #4


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    Homework Helper

    Your pressure seems to be correct this corresponds to a mass of about 250 grams. Quite a lot for such a delicate membrane would'nt you think?
  6. Nov 23, 2007 #5


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    Is it 2.5 kN?
  7. Nov 23, 2007 #6
    i think its only 2.5 n as i made my transformation of 45 kpa to 45000 pa
  8. Nov 23, 2007 #7


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    There is an example in the textbook.. the one by knights jones and field.. is that what you're using? anyway, there was an example in the book where it was Pa multiplied by meters squared and equaled newtons... i dont have the book or else i'd tell you the page!
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