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!

Angular momentum of the earth

  1. Apr 22, 2005 #1
    I'm stuck on the second part of a problem and can't seem to get the right answer:

    Calculate the magnitude of the angular momentum of the earth due to its rotation around an axis through the north and south poles. Treat the earth as a uniform sphere of radius 6.38*10^6 that makes one revolution in 24.0 hours. (m=5.97*10^24)

    I got the answer 1.77*10^34 but it's wrong :(
     
  2. jcsd
  3. Apr 22, 2005 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Show your work. Explain how you got your answer.
     
  4. Apr 22, 2005 #3
    I found the moment of Inertia (mr^2) to be = 2.43*10^38. Then found the angular velocity to be (2pi)/(24*60*60). Using the equation I=m*r^2, I got 1.77*10^34
     
  5. Apr 22, 2005 #4

    Doc Al

    User Avatar

    Staff: Mentor

    That's the moment of inertial of a particle, not a solid sphere about its center. The one you want is [itex]I = 2/5 m r^2[/itex].
     
  6. Apr 22, 2005 #5
    Thanks for that! I tried looking on the internet for the moment of Inertia of the earth and was getting all sorts of weird numbers no wonder it wasn't working.
     
  7. Apr 22, 2005 #6

    jtbell

    User Avatar

    Staff: Mentor

    Every "General Physics" textbook I've ever seen has a table of formulas for moment of inertia of various shapes of objects. What kind of a course are you taking?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Angular momentum of the earth
  1. Angular momentume (Replies: 7)

  2. Angular momentum (Replies: 1)

Loading...