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!

Pressure on a submarine window

  1. Aug 6, 2013 #1
    1. A research submarine has a 20cm diameter window, 8cm thick. The manufacturer says the window can withstand forces up to 10^6N. What is the submarine's maximum safe depth? The pressure inside the submarine is maintained at 1atm.



    2. Relevant equationsP = P(atmosphere) + ρ*g*h


    3. I tried finding the pressure on the window, using P = F/A and got the maximum pressure the submarine window can handle as P = 10^6/(pi*(0.1)^2) = 3.18*10^7 Pa.
    I then used P = P(atmosphere) + ρ*g*h
    and substitued, P as 3.18*10^7, P(atmosphere) as 101,300, ρ(used density of seawater) as 1030, g as 9.8 and found h to be approximately 3140m.
    The solutions found h to be 3153m.
    I don't know where I have gone wrong...
     
  2. jcsd
  3. Aug 6, 2013 #2
    Did you take into account that the internal pressure is 1 atm?
     
  4. Aug 6, 2013 #3
    Thanks I didn't consider it before but thinking about it in force perspective so it made more sense. I did Net force = Force ourtside window - Force inside window. Therefore 10^6 = Fout - Fin. Then Fout = P(outside)*A and Fin = P(inside)*A. 10^6/A = P(outside) - P(inside). 10^6/A = ρ*g*h + P(atmosphere) - P(inside submarine). Now P(atmosphere) = 1atm=P(inside submarine), ρ.=1030 Therefore 10^6/A = ρ*g*h.
    Then I h to be (10^6)/(pi*(0.1^2)*9.8*1030) = 3153m.
    THANK YOU VERY MUCH!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Pressure on a submarine window
Loading...