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!

Heat: efficiency

  1. Jun 28, 2003 #1

    Dx

    User Avatar

    A heat engine has efficiency of 35% and recieves 150J heat per cycle. how much work dos it perfrom in each cycle?

    I said 52.5J

    w=e*q_h =
    .35 * 150 =
    52.5
    its wrong

    what did i do wrong with this calculation. unless it mean 150J of put in. can anyone please explain this to me.
    TY!
    dx :wink:
     
  2. jcsd
  3. Jun 28, 2003 #2

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Can you post the definition of efficiency from your book?
     
  4. Jun 28, 2003 #3

    Dx

    User Avatar

    efficiency(e) = W(work out) / Q_H(work in)
     
  5. Jun 28, 2003 #4

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    That's what I thought. OK, just plug-n-chug.

    (You know, it's always possible that the book is wrong!)
     
  6. Jun 28, 2003 #5

    Dx

    User Avatar

    I thought i did that like shown but aparently its not right. I just wanted to know does your answer match mine?
    Dx:wink:
     
  7. Jun 28, 2003 #6

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

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

Have something to add?



Similar Discussions: Heat: efficiency
Loading...