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!

Calculation of atmospheric presure

  1. Sep 26, 2016 #1
    1. The problem statement, all variables and given/known data
    Taking atmospheric pressure at sea level to be 1x10^5 pa CPa and the density of air at sea level to be
    about 1.2kg/m^3,estimate the atmospheric pressure in London 550m above sea level. For this calculation, it is easiest to assume that air density doesn’t change with height – briefly discuss
    the validity of this assumption

    2. Relevant equations
    patm= rho g h

    3. The attempt at a solution
    Well, I did p=pgh- 1.2x9.8x550 and substracted the answer by the atmosperhic pressure of the sea to get the answer? Am I right?
     
  2. jcsd
  3. Sep 26, 2016 #2

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Don't know, you haven't stated your result. It's certainly one way to "estimate" atmospheric pressure in London.
     
  4. Sep 26, 2016 #3
    Well alright thanks for reply.. here the results i got above
    so for p atmospheric i got- 1.2kg/m^3x9.8m/s^2x 550m= 6648pa then i substractfrom the very given pressure that is 1x10^5pa-6648pa= 93352pa pressure of london?
     
  5. Sep 26, 2016 #4

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    You might want, in addition, to pay attention to significant figures.
     
  6. Sep 26, 2016 #5
    you mean i convert to kpa?
     
  7. Sep 26, 2016 #6

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Not units --- significant figures.
     
  8. Sep 26, 2016 #7
    I don't understand. 93352pa= 92.5kpa?
     
  9. Sep 26, 2016 #8

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Yes. I'll re-emphasize the "might," I've no idea how picky your instructor "might" be.
     
  10. Sep 26, 2016 #9
    Oh ok, thanks i gave u a like.
     
  11. Sep 26, 2016 #10

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted