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: Find force (N) of atmosphere on area

  1. May 4, 2010 #1
    1. The problem statement, all variables and given/known data

    Your eardrum has an area of about 53 mm2. Sounds become painful to your ear when the pressure variations that are involved in sound reach 200 Pa above and below normal air pressure. At this level, called the threshold of pain, how much force is exerted on your eardrum?

    2. Relevant equations

    Pressure=[tex]\frac{Force}{Area}[/tex]

    3. The attempt at a solution

    F=PA
    F= 101000N/m^2 (.053m^2)
    F= 5353 N

    I've tried normal atmosphere above and below 200Pa. The answer isn't correct according to wileyplus. I'm obviously doing it wrong, so whats wrong with my equation?
     
  2. jcsd
  3. May 4, 2010 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Hi Calhoun295! :smile:

    (try using the X2 tag just above the Reply box :wink:)
    No, you'll have Patm on one side of your eardrum, and Patm ± 200 on the other side … net pressure = ±200. :wink:
     
  4. May 4, 2010 #3
    Also note that [tex]53 mm^2= 53 \cdot ((10^{-3} m)^2) = 53\cdot 10^{-6} m^2[/tex]
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook