1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Pressure of a snorkeler

  1. Oct 28, 2007 #1
    1. The problem statement, all variables and given/known data
    The human lungs can function satisfactorily up to a limit where the pressure difference between the outside and inside of the lungs is 1/20 of an atmosphere. If a diver uses a snorkel for breathing, how far below the water can she swim? Assume the diver is in salt water whose density is 1029 kg/m3.

    2. Relevant equations
    1 atm = 1.013e5 Pa
    1/20 atm = 5065 Pa
    P1 + P2 = gauge pressure
    P = density*gravity*height
    P = Force/Area
    3. The attempt at a solution

    So the pressure in the lungs minus the pressure outside the lungs must be less than 5065 Pa. If
    P1-P2 = 5065 and
    P2 = 1029*height
    these should just be combined somehow. However, how do I know what the pressure is inside the lungs? If I use 1 atm,
    1.013e5 - 1029(g)(h) = 5065
    96235 = 1029(9.8)(h)
    h = 9.54 m
    But this is not correct. Does anyone have a suggestion?
  2. jcsd
  3. Oct 28, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I would expect the pressure under water to be greater so I'd take the under water pressure away from the pressure in the lungs. The difference is not that great however.
  4. Oct 29, 2007 #3
    Ok so any other ideas?
  5. Oct 29, 2007 #4


    User Avatar
    Science Advisor

    I came up with about 0.5 meters.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook