Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Torque and joules

  1. Apr 22, 2014 #1
    Wikipedia says that the unit of magnetic dipole moments is calculated by Joule/B that means that the torque is measured by joules
    I really doubt that, it seems non sense.
     
  2. jcsd
  3. Apr 22, 2014 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Torque has units of Force*distance. Usually expressed as N-m, but equivalent to Joules though I do not recommend that usage. (Usually Joule is reserved for energy, not torque!)
     
  4. Apr 22, 2014 #3

    How is that ???
     
  5. Apr 22, 2014 #4
    Energy equals the product of the force and the displacement along which the force is done

    And the torque is the product of the force and displacement between the two forces, the concept of displacement isn't the same in both cases
     
    Last edited: Apr 22, 2014
  6. Apr 22, 2014 #5

    Doc Al

    User Avatar

    Staff: Mentor

    1 N-m = 1 J
     
  7. Apr 22, 2014 #6

    Doc Al

    User Avatar

    Staff: Mentor

    We are talking about units, not about the definitions of torque and energy. (That's why energy is Joules while torque is in N-m, despite the fact the units are equivalent.)
     
  8. Apr 22, 2014 #7
    The units are are the same but their definitions are different
     
  9. Apr 22, 2014 #8

    Doc Al

    User Avatar

    Staff: Mentor

  10. Apr 22, 2014 #9

    Doc Al

    User Avatar

    Staff: Mentor

    Right. (For example, one is a vector while the other is a scalar.)
     
  11. Apr 22, 2014 #10
    But I think that it's totally wrong to say that torque is measured by joules not just "unrecommended"
     
  12. Apr 22, 2014 #11
    Thanks jersey :smile:
     
  13. Apr 22, 2014 #12

    adjacent

    User Avatar
    Gold Member

    jersey?
     
  14. Apr 22, 2014 #13

    russ_watters

    User Avatar

    Staff: Mentor

    I'm not seeing that (I'm seeing n-m), can you link and quote it please.
     
  15. Apr 22, 2014 #14

    UltrafastPED

    User Avatar
    Science Advisor
    Gold Member

  16. Apr 22, 2014 #15
  17. Apr 22, 2014 #16
  18. Apr 22, 2014 #17
  19. Apr 22, 2014 #18
    However, how is work done by a torque calculated ??

    I know that work is calculated by f.d
    I'm unable to apply that on non linear motion
     
  20. Apr 22, 2014 #19

    jtbell

    User Avatar

    Staff: Mentor

    What is the equivalent of "distance" if something rotates instead of moving along a line?
     
  21. Apr 22, 2014 #20

    BiGyElLoWhAt

    User Avatar
    Gold Member

    Angular displacement i.e. Radians

    [itex]KE_{angular} = \frac{1}{2}I\omega ^2[/itex]
     
    Last edited: Apr 22, 2014
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Torque and joules
  1. Negative Joule (Replies: 6)

  2. Nm into Joules (Replies: 13)

  3. Newton to Joule ? (Replies: 3)

  4. Joules and watts (Replies: 7)

Loading...