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: Unit conversion

  1. Sep 17, 2007 #1
    1. The problem statement, all variables and given/known data

    "convert the gas constant, R, into units of ft•lbf/lbmol•°R.
    Data: R = 8.31451 J/mol•°C.
    "

    2. Relevant equations

    I know 1 J = 0.22481 lbf

    but what's R, and how they can get ft and lb in there?

    3. The attempt at a solution
     
  2. jcsd
  3. Sep 17, 2007 #2

    learningphysics

    User Avatar
    Homework Helper

    Is that exactly how the question is given? I'm confused by lbmol... shouldn't it just be mol ?

    Also,

    1 N = 0.22481 lbf, not 1 J.
     
  4. Sep 17, 2007 #3
    yes, I just copy pasted from that assignment(given to us in a word document)
    I think it is then lb mol
     
  5. Sep 18, 2007 #4

    learningphysics

    User Avatar
    Homework Helper

    These are some tricky units. A regular mole in SI units = 1 gram mole. 1 K = 1.8 R. R is rankine a scale of temperature.
     
  6. Sep 18, 2007 #5
    Thanks a lot!

    yesterday, I forgot to see the unit conversion handouts provided, and these were in there.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook