1. Not finding help here? Sign up for a free 30min 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!

How this unit comes like that ?

  1. Nov 3, 2012 #1
    How this unit comes

    R = specific volume X (pressure / Temperature )

    0.9m^3/kg (1.3X10^5 N/m^2 / 408 K )

    R = 286 KJ/KgK

    please can any one explain to me how the unit ( KJ/KgK ) comes ??
     
  2. jcsd
  3. Nov 3, 2012 #2

    Borek

    User Avatar

    Staff: Mentor

    kJ/(kg*K) - looks quite straightforward, where is the problem?
     
  4. Nov 3, 2012 #3
    Hi sir .. I know the unit is correct but when I try to solve by my self I don't get that uint

    please help ..
     
  5. Nov 3, 2012 #4
    r = volume * pressure / temperature
    = (length*length*length)/mass * Newtons/(length*length) / temperature
    = length*Newtons/(temperature * mass)

    = Joules/(temperature * mass)
     
  6. Nov 3, 2012 #5

    Borek

    User Avatar

    Staff: Mentor

    Show what you did then and we will try to find out where did you get wrong.
     
  7. Nov 3, 2012 #6
    1 Joule = 1 N-m
     
  8. Nov 4, 2012 #7

    Borek

    User Avatar

    Staff: Mentor

    Dash that looks like a minus is not the luckiest selection of the symbol in this context.

    1 Joule = 1 Newton * m

    is much less ambiguous.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook